1
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Zhou A, Sun Z, Sun L. Stable organic radical qubits and their applications in quantum information science. Innovation (N Y) 2024; 5:100662. [PMID: 39091459 PMCID: PMC11292369 DOI: 10.1016/j.xinn.2024.100662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 06/20/2024] [Indexed: 08/04/2024] Open
Abstract
The past century has witnessed the flourishing of organic radical chemistry. Stable organic radicals are highly valuable for quantum technologies thanks to their inherent room temperature quantum coherence, atomic-level designability, and fine tunability. In this comprehensive review, we highlight the potential of stable organic radicals as high-temperature qubits and explore their applications in quantum information science, which remain largely underexplored. Firstly, we summarize known spin dynamic properties of stable organic radicals and examine factors that influence their electron spin relaxation and decoherence times. This examination reveals their design principles and optimal operating conditions. We further discuss their integration in solid-state materials and surface structures, and present their state-of-the-art applications in quantum computing, quantum memory, and quantum sensing. Finally, we analyze the primary challenges associated with stable organic radical qubits and provide tentative insights to future research directions.
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Affiliation(s)
- Aimei Zhou
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Zhecheng Sun
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Lei Sun
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou 310030, China
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2
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Li BY, Dickerson CE, Shin AJ, Zhao C, Shen Y, He Y, Diaconescu PL, Alexandrova AN, Caram JR. Elucidating ultranarrow 2F 7/2 to 2F 5/2 absorption in ytterbium(iii) complexes. Chem Sci 2024; 15:12451-12458. [PMID: 39118624 PMCID: PMC11304733 DOI: 10.1039/d4sc02944e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 06/30/2024] [Indexed: 08/10/2024] Open
Abstract
Achieving ultranarrow absorption linewidths in the condensed phase enables optical state preparation of specific non-thermal states, a prerequisite for quantum-enabled technologies. The 4f orbitals of lanthanide(iii) complexes are often referred to as "atom-like," reflecting their isolated nature, and are promising substrates for the optical preparation of specific quantum states. To better understand the photophysical properties of 4f states and assess their potential for quantum applications, theoretical building blocks are required for rapid screening. In this study, an atomic-level perturbative calculation (i.e., spin-orbit crystal field, SOCF) is applied to various Yb(iii) complexes to investigate their linear absorption and emission through a fitting mechanism of their experimentally determined transition energies and oscillator strengths. In particular, the optical properties of (thiolfan)YbCl(THF) (thiolfan = 1,1'-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene), a recently reported complex with an ultranarrow optical linewidth, are computed and compared to those of other Yb(iii) compounds. Through a transition energy sampling study, major contributors to the optical linewidth are identified. We observe particularly isolated f-f transitions and narrow linewidths, which we attribute to two distinct factors. Firstly, the ultra-high atomic similarity of the orbitals involved in the optical transition, along with the presence of an anisotropic crystal field, collectively contribute to the observed narrow transitions. Secondly, we note highly correlated excited-ground energy fluctuations that serve to greatly suppress inhomogeneous line-broadening. This article illustrates how SOCF can be used as a low-cost method to probe the influence of crystal field environment on the optical properties of Yb(iii) complexes to assist the development of novel lanthanide series quantum materials.
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Affiliation(s)
- Barry Y Li
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Claire E Dickerson
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Ashley J Shin
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Changling Zhao
- Department of Physics and Astronomy, University of California Los Angeles California 90095 USA
| | - Yi Shen
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Yongjia He
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Paula L Diaconescu
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
- Department of Materials Science and Engineering, University of California Los Angeles California 90095 USA
| | - Justin R Caram
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
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3
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Laorenza DW, Mullin KR, Weiss LR, Bayliss SL, Deb P, Awschalom DD, Rondinelli JM, Freedman DE. Coherent spin-control of S = 1 vanadium and molybdenum complexes. Chem Sci 2024:d4sc03107e. [PMID: 39144462 PMCID: PMC11318652 DOI: 10.1039/d4sc03107e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Accepted: 07/25/2024] [Indexed: 08/16/2024] Open
Abstract
The burgeoning field of quantum sensing hinges on the creation and control of quantum bits. To date, the most well-studied quantum sensors are optically active, paramagnetic defects residing in crystalline hosts. We previously developed analogous optically addressable molecules featuring a ground-state spin-triplet centered on a Cr4+ ion with an optical-spin interface. In this work, we evaluate isovalent V3+ and Mo4+ congeners, which offer unique advantages, such as an intrinsic nuclear spin for V3+ or larger spin-orbit coupling for Mo4+, as optically addressable spin systems. We assess the ground-state spin structure and dynamics for each complex, illustrating that all of these spin-triplet species can be coherently controlled. However, unlike the Cr4+ derivatives, these pseudo-tetrahedral V3+ and Mo4+ complexes exhibit no measurable emission. Coupling absorption spectroscopy with computational predictions, we investigate why these complexes exhibit no detectable photoluminescence. These cumulative results suggest that design of future V3+ complexes should target pseudo-tetrahedral symmetries using bidentate or tridentate ligand scaffolds, ideally with deuterated or fluorinated ligand environments. We also suggest that spin-triplet Mo4+, and by extension W4+, complexes may not be suitable candidate optically addressable qubit systems due to their low energy spin-singlet states. By understanding the failures and successes of these systems, we outline additional design features for optically addressable V- or Mo-based molecules to expand the library of tailor-made quantum sensors.
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Affiliation(s)
- Daniel W Laorenza
- Department of Chemistry, Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
| | - Kathleen R Mullin
- Department of Materials Science and Engineering, Northwestern University Evanston Illinois 60208 USA
| | - Leah R Weiss
- Pritzker School of Molecular Engineering, University of Chicago Chicago Illinois 60637 USA
- Advanced Institute for Materials Research (AIMR-WPI), Tohoku University Sendai 980-8577 Japan
| | - Sam L Bayliss
- Pritzker School of Molecular Engineering, University of Chicago Chicago Illinois 60637 USA
- James Watt School of Engineering, University of Glasgow Glasgow G12 8QQ UK
| | - Pratiti Deb
- Pritzker School of Molecular Engineering, University of Chicago Chicago Illinois 60637 USA
- Department of Physics, University of Chicago Chicago Illinois 60637 USA
| | - David D Awschalom
- Pritzker School of Molecular Engineering, University of Chicago Chicago Illinois 60637 USA
- Department of Physics, University of Chicago Chicago Illinois 60637 USA
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory Lemont Illinois 60439 USA
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University Evanston Illinois 60208 USA
| | - Danna E Freedman
- Department of Chemistry, Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
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4
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Budakian R, Finkler A, Eichler A, Poggio M, Degen CL, Tabatabaei S, Lee I, Hammel PC, Eugene SP, Taminiau TH, Walsworth RL, London P, Bleszynski Jayich A, Ajoy A, Pillai A, Wrachtrup J, Jelezko F, Bae Y, Heinrich AJ, Ast CR, Bertet P, Cappellaro P, Bonato C, Altmann Y, Gauger E. Roadmap on nanoscale magnetic resonance imaging. NANOTECHNOLOGY 2024; 35:412001. [PMID: 38744268 DOI: 10.1088/1361-6528/ad4b23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 05/14/2024] [Indexed: 05/16/2024]
Abstract
The field of nanoscale magnetic resonance imaging (NanoMRI) was started 30 years ago. It was motivated by the desire to image single molecules and molecular assemblies, such as proteins and virus particles, with near-atomic spatial resolution and on a length scale of 100 nm. Over the years, the NanoMRI field has also expanded to include the goal of useful high-resolution nuclear magnetic resonance (NMR) spectroscopy of molecules under ambient conditions, including samples up to the micron-scale. The realization of these goals requires the development of spin detection techniques that are many orders of magnitude more sensitive than conventional NMR and MRI, capable of detecting and controlling nanoscale ensembles of spins. Over the years, a number of different technical approaches to NanoMRI have emerged, each possessing a distinct set of capabilities for basic and applied areas of science. The goal of this roadmap article is to report the current state of the art in NanoMRI technologies, outline the areas where they are poised to have impact, identify the challenges that lie ahead, and propose methods to meet these challenges. This roadmap also shows how developments in NanoMRI techniques can lead to breakthroughs in emerging quantum science and technology applications.
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Affiliation(s)
- Raffi Budakian
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
- Institute for Quantum Computing, University of Waterloo, Waterloo, Canada
| | - Amit Finkler
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Alexander Eichler
- Institute for Solid State Physics, ETH Zurich, Otto-Stern-Weg 1, 8093 Zurich, Switzerland
| | - Martino Poggio
- Department of Physics and Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland
| | - Christian L Degen
- Institute for Solid State Physics, ETH Zurich, Otto-Stern-Weg 1, 8093 Zurich, Switzerland
| | - Sahand Tabatabaei
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
- Institute for Quantum Computing, University of Waterloo, Waterloo, Canada
| | - Inhee Lee
- Department of Physics, The Ohio State University, Columbus, OH 43210, United States of America
| | - P Chris Hammel
- Department of Physics, The Ohio State University, Columbus, OH 43210, United States of America
| | - S Polzik Eugene
- Niels Bohr Institute, University of Copenhagen, 17, Copenhagen, 2100, Denmark
| | - Tim H Taminiau
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Netherlands
| | - Ronald L Walsworth
- University of Maryland 2218 Kim Engineering Building, College Park, MD 20742, United States of America
| | - Paz London
- Department of Physics, University of California, Santa Barbara, CA 93106, United States of America
| | - Ania Bleszynski Jayich
- Department of Physics, University of California, Santa Barbara, CA 93106, United States of America
| | - Ashok Ajoy
- Department of Chemistry, University of California, Berkeley, CA 97420, United States of America
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, United States of America
- Quantum Information Science Program, CIFAR, 661 University Ave., Toronto, ON M5G 1M1, Canada
| | - Arjun Pillai
- Department of Chemistry, University of California, Berkeley, CA 97420, United States of America
| | - Jörg Wrachtrup
- 3. Physikalisches Institut, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Fedor Jelezko
- Institute of Quantum Optics, Ulm University, Ulm, 89081, Germany
| | - Yujeong Bae
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Andreas J Heinrich
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Christian R Ast
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Patrice Bertet
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette, France
| | - Paola Cappellaro
- Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States of America
| | - Cristian Bonato
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, HeriotWatt University, Edinburgh EH14 4AS, United Kingdom
| | - Yoann Altmann
- Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Erik Gauger
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, HeriotWatt University, Edinburgh EH14 4AS, United Kingdom
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5
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Miao Z, Pan X, Kamenetska M. Conductance and assembly of quasi-1D coordination chain molecular junctions with triazole derivatives. Dalton Trans 2024; 53:10453-10461. [PMID: 38868899 DOI: 10.1039/d4dt01085j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Incorporating transition metal atoms into metal-molecule-metal junctions presents opportunities for exploring the electronic properties of coordination complexes, organometallics and metal-organic materials on the single molecule level. Recent single molecule conductance studies have shown that in situ incorporation of electrode metal atoms into coordination chains formed in the junction can occur with deprotonated, negatively charged organic ligands, such as the imidazolate (Im-) anion. However, the mechanism and chemical principles, such as the role of the charge state of the ligand, for the construction of such coordination chains are still debated. Here, we probe the role of the ligand charge state and electronic structure in single-molecule conductance and formation of metal-molecule coordination chains. We perform break junction measurements with triazole isomers, which can bridge junctions both in their neutral and charged forms, and find that prior deprotonation of the ligands is not required for coordination complex assembly, but can affect the molecular conductance and junction formation probability. Our results indicate that coordination chains can form with neutral ligands, as long as the electron density in the frontier MOs is concentrated at the binding sites and along the direction of pulling, promoting ligand binding and incorporation of gold atoms into the junction during elongation. Our findings may provide insight into design principles for in situ assembled molecular wires with transition metal atoms and open the door to electronic and spintronic studies of such materials.
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Affiliation(s)
- Zelin Miao
- Division of Materials Science and Engineering, Boston University, Boston, Massachusetts, 02215, USA.
| | - Xiaoyun Pan
- Department of Chemistry, Boston University, Boston, Massachusetts, 02215, USA
| | - Maria Kamenetska
- Division of Materials Science and Engineering, Boston University, Boston, Massachusetts, 02215, USA.
- Department of Chemistry, Boston University, Boston, Massachusetts, 02215, USA
- Department of Physics, Boston University, Boston, Massachusetts, 02215, USA
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6
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Mayländer M, Khariushin IV, Vargas Jentzsch A, Richert S. Correlation between Radical and Quartet State Coherence Times in Photogenerated Triplet-Radical Conjugates. J Phys Chem Lett 2024; 15:5935-5938. [PMID: 38809777 DOI: 10.1021/acs.jpclett.4c01353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Molecular quartet states, generated by photoexcitation of chromophore-radical conjugates, have been shown to exhibit attractive properties for applications in the field of molecular spintronics. Many of these applications, such as quantum sensing, require a coherent manipulation of the spin system, implying the need to control the quartet state spin coherence properties. By examining the influence of structural and matrix-related factors, we demonstrate a correlation between the coherence decay of the photogenerated quartet state and that of the tethered stable radical, paving the way for a rational design of photogenerated molecular three-spin systems with optimized coherence properties.
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Affiliation(s)
- Maximilian Mayländer
- Institute of Physical Chemistry, University of Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Ivan V Khariushin
- SAMS Research Group, Université de Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67000 Strasbourg, France
| | - Andreas Vargas Jentzsch
- SAMS Research Group, Université de Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67000 Strasbourg, France
| | - Sabine Richert
- Institute of Physical Chemistry, University of Freiburg, Albertstraße 21, 79104 Freiburg, Germany
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7
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Poh YR, Morozov D, Kazmierczak NP, Hadt RG, Groenhof G, Yuen-Zhou J. Alternant Hydrocarbon Diradicals as Optically Addressable Molecular Qubits. J Am Chem Soc 2024; 146:15549-15561. [PMID: 38798142 DOI: 10.1021/jacs.4c04360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
High-spin molecules allow for bottom-up qubit design and are promising platforms for magnetic sensing and quantum information science. Optical addressability of molecular electron spins has also been proposed in first-row transition-metal complexes via optically detected magnetic resonance (ODMR) mechanisms analogous to the diamond-nitrogen-vacancy color center. However, significantly less progress has been made on the front of metal-free molecules, which can deliver lower costs and milder environmental impacts. At present, most luminescent open-shell organic molecules are π-diradicals, but such systems often suffer from poor ground-state open-shell characters necessary to realize a stable ground-state molecular qubit. In this work, we use alternancy symmetry to selectively minimize radical-radical interactions in the ground state, generating π-systems with high diradical characters. We call them m-dimers, referencing the need to covalently link two benzylic radicals at their meta carbon atoms for the desired symmetry. Through a detailed electronic structure analysis, we find that the excited states of alternant hydrocarbon m-diradicals contain important symmetries that can be used to construct ODMR mechanisms leading to ground-state spin polarization. The molecular parameters are set in the context of a tris(2,4,6-trichlorophenyl)methyl (TTM) radical dimer covalently tethered at the meta position, demonstrating the feasibility of alternant m-diradicals as molecular color centers.
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Affiliation(s)
- Yong Rui Poh
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Dmitry Morozov
- Terra Quantum AG, Kornhausstrasse 25, St. Gallen 9000, Switzerland
| | - Nathanael P Kazmierczak
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Ryan G Hadt
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Gerrit Groenhof
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, Jyväskylä 40014, Finland
| | - Joel Yuen-Zhou
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
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8
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Eaves JD. Multielectron Dynamics in the Condensed Phase: Quantum Structure-Function Relationships. Annu Rev Phys Chem 2024; 75:437-456. [PMID: 38941526 DOI: 10.1146/annurev-physchem-042018-052515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024]
Abstract
Quantum information promises dramatic advances in computing last seen in the digital revolution, but quantum hardware is fragile, noisy, and resource intensive. Chemistry has a role in developing new materials for quantum information that are robust to noise, scalable, and operable in ambient conditions. While molecular structure is the foundation for understanding mechanism and reactivity, molecular structure/quantum function relationships remain mostly undiscovered. Using singlet fission as a specific example of a multielectron process capable of producing long-lived spin-entangled electronic states at high temperatures, I describe how to exploit molecular structure and symmetry to gain quantum function and how some principles learned from singlet fission apply more broadly to quantum science.
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Affiliation(s)
- Joel D Eaves
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA;
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9
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Cho FH, Park J, Oh S, Yu J, Jeong Y, Colazzo L, Spree L, Hommel C, Ardavan A, Boero G, Donati F. A continuous-wave and pulsed X-band electron spin resonance spectrometer operating in ultra-high vacuum for the study of low dimensional spin ensembles. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:063904. [PMID: 38864723 DOI: 10.1063/5.0189974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 05/09/2024] [Indexed: 06/13/2024]
Abstract
We report the development of a continuous-wave and pulsed X-band electron spin resonance (ESR) spectrometer for the study of spins on ordered surfaces down to cryogenic temperatures. The spectrometer operates in ultra-high vacuum and utilizes a half-wavelength microstrip line resonator realized using epitaxially grown copper films on single crystal Al2O3 substrates. The one-dimensional microstrip line resonator exhibits a quality factor of more than 200 at room temperature, close to the upper limit determined by radiation losses. The surface characterizations of the copper strip of the resonator by atomic force microscopy, low-energy electron diffraction, and scanning tunneling microscopy show that the surface is atomically clean, flat, and single crystalline. Measuring the ESR spectrum at 15 K from a few nm thick molecular film of YPc2, we find a continuous-wave ESR sensitivity of 2.6 × 1011 spins/G · Hz1/2, indicating that a signal-to-noise ratio of 3.9 G · Hz1/2 is expected from a monolayer of YPc2 molecules. Advanced pulsed ESR experimental capabilities, including dynamical decoupling and electron-nuclear double resonance, are demonstrated using free radicals diluted in a glassy matrix.
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Affiliation(s)
- Franklin H Cho
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Ewha Womans University, Seoul 03760, South Korea
| | - Juyoung Park
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Department of Physics, Ewha Womans University, Seoul 03760, South Korea
| | - Soyoung Oh
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Department of Physics, Ewha Womans University, Seoul 03760, South Korea
| | - Jisoo Yu
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Department of Physics, Ewha Womans University, Seoul 03760, South Korea
| | - Yejin Jeong
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Department of Physics, Ewha Womans University, Seoul 03760, South Korea
| | - Luciano Colazzo
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Ewha Womans University, Seoul 03760, South Korea
| | - Lukas Spree
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Ewha Womans University, Seoul 03760, South Korea
| | - Caroline Hommel
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Ewha Womans University, Seoul 03760, South Korea
| | - Arzhang Ardavan
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Giovanni Boero
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Fabio Donati
- Center for Quantum Nanoscience, Institute for Basic Science, Seoul 03760, South Korea
- Department of Physics, Ewha Womans University, Seoul 03760, South Korea
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10
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Murto P, Li B, Fu Y, Walker LE, Brown L, Bond AD, Zeng W, Chowdhury R, Cho HH, Yu CP, Grey CP, Friend RH, Bronstein H. Steric Control of Luminescence in Phenyl-Substituted Trityl Radicals. J Am Chem Soc 2024; 146:13133-13141. [PMID: 38695282 PMCID: PMC11099960 DOI: 10.1021/jacs.4c00292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 05/16/2024]
Abstract
Triphenylmethyl (trityl) radicals have shown potential for use in organic optoelectronic applications, but the design of practical trityl structures has been limited to donor/radical charge-transfer systems due to the poor luminescence of alternant symmetry hydrocarbons. Here, we circumvent the symmetry-forbidden transition of alternant hydrocarbons via excited-state symmetry breaking in a series of phenyl-substituted tris(2,4,6-trichlorophenyl)methyl (TTM) radicals. We show that 3-fold phenyl substitution enhances the emission of the TTM radical and that steric control modulates the optical properties in these systems. Simple ortho-methylphenyl substitution boosts the photoluminescence quantum efficiency from 1% (for TTM) to 65% at a peak wavelength of 612 nm (for 2-T3TTM) in solution. In the crystalline solid state, the neat 2-T3TTM radical shows a remarkably high photoluminescence quantum efficiency of 25% for emission peaking at 706 nm. This has implications in the design of aryl-substituted radical structures where the electronic coupling of the substituents influences variables such as emission, charge transfer, and spin interaction.
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Affiliation(s)
- Petri Murto
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Biwen Li
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Yao Fu
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Lucy E. Walker
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Laura Brown
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Andrew D. Bond
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Weixuan Zeng
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | | | - Hwan-Hee Cho
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Craig P. Yu
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Clare P. Grey
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
| | - Richard H. Friend
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
| | - Hugo Bronstein
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
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11
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Zakrzewski J, Liberka M, Wang J, Chorazy S, Ohkoshi SI. Optical Phenomena in Molecule-Based Magnetic Materials. Chem Rev 2024; 124:5930-6050. [PMID: 38687182 PMCID: PMC11082909 DOI: 10.1021/acs.chemrev.3c00840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Since the last century, we have witnessed the development of molecular magnetism which deals with magnetic materials based on molecular species, i.e., organic radicals and metal complexes. Among them, the broadest attention was devoted to molecule-based ferro-/ferrimagnets, spin transition materials, including those exploring electron transfer, molecular nanomagnets, such as single-molecule magnets (SMMs), molecular qubits, and stimuli-responsive magnetic materials. Their physical properties open the application horizons in sensors, data storage, spintronics, and quantum computation. It was found that various optical phenomena, such as thermochromism, photoswitching of magnetic and optical characteristics, luminescence, nonlinear optical and chiroptical effects, as well as optical responsivity to external stimuli, can be implemented into molecule-based magnetic materials. Moreover, the fruitful interactions of these optical effects with magnetism in molecule-based materials can provide new physical cross-effects and multifunctionality, enriching the applications in optical, electronic, and magnetic devices. This Review aims to show the scope of optical phenomena generated in molecule-based magnetic materials, including the recent advances in such areas as high-temperature photomagnetism, optical thermometry utilizing SMMs, optical addressability of molecular qubits, magneto-chiral dichroism, and opto-magneto-electric multifunctionality. These findings are discussed in the context of the types of optical phenomena accessible for various classes of molecule-based magnetic materials.
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Affiliation(s)
- Jakub
J. Zakrzewski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Michal Liberka
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Junhao Wang
- Department
of Materials Science, Faculty of Pure and Applied Science, University of Tsukuba, 1-1-1 Tonnodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Szymon Chorazy
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Shin-ichi Ohkoshi
- Department
of Chemistry, School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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12
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Bian K, Zheng W, Chen X, Zhang S, Stöhr R, Denisenko A, Yang S, Wrachtrup J, Jiang Y. A scanning probe microscope compatible with quantum sensing at ambient conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:053707. [PMID: 38819258 DOI: 10.1063/5.0202756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024]
Abstract
We designed and built up a new type of ambient scanning probe microscope (SPM), which is fully compatible with state-of-the-art quantum sensing technology based on the nitrogen-vacancy (NV) centers in diamond. We chose a qPlus-type tuning fork (Q up to ∼4400) as the current/force sensor of SPM for its high stiffness and stability under various environments, which yields atomic resolution under scanning tunneling microscopy mode and 1.2-nm resolution under atomic force microscopy mode. The tip of SPM can be used to directly image the topography of nanoscale targets on diamond surfaces for quantum sensing and to manipulate the electrostatic environment of NV centers to enhance their sensitivity up to a single proton spin. In addition, we also demonstrated scanning magnetometry and electrometry with a spatial resolution of ∼20 nm. Our new system not only paves the way for integrating atomic/molecular-scale color-center qubits onto SPM tips to produce quantum tips but also provides the possibility of fabricating color-center qubits with nanoscale or atomic precision.
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Affiliation(s)
- Ke Bian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Wentian Zheng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Xiakun Chen
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Shichen Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Rainer Stöhr
- Third Institute of Physics, University of Stuttgart and Institute for Quantum Science and Technology (IQST), Stuttgart 70569, Germany
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Andrej Denisenko
- Third Institute of Physics, University of Stuttgart and Institute for Quantum Science and Technology (IQST), Stuttgart 70569, Germany
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Sen Yang
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Jörg Wrachtrup
- Third Institute of Physics, University of Stuttgart and Institute for Quantum Science and Technology (IQST), Stuttgart 70569, Germany
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Ying Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
- New Cornerstone Science Laboratory, Peking University, Beijing 100871, China
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13
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Imperato M, Nicolini A, Boniburini M, Sartini D, Benassi E, Chiesa M, Gigli L, Liao YK, Raza A, Salvadori E, Sorace L, Cornia A. Dual Structure of a Vanadyl-Based Molecular Qubit Containing a Bis(β-diketonato) Ligand. Inorg Chem 2024; 63:7912-7925. [PMID: 38620046 DOI: 10.1021/acs.inorgchem.4c00834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
We designed [VO(bdhb)] (1') as a new electronic qubit containing an oxovanadium(IV) ion (S = 1/2) embraced by a single bis(β-diketonato) ligand [H2bdhb = 1,3-bis(3,5-dioxo-1-hexyl)benzene]. The synthesis afforded three different crystal phases, all of which unexpectedly contain dimers with formula [(VO)2(bdhb)2] (1). A trigonal form (1h) with a honeycomb structure and 46% of solvent-accessible voids quantitatively transforms over time into a monoclinic solvatomorph 1m and minor amounts of a triclinic solventless phase (1a). In a static magnetic field, 1h and 1m have detectably slow magnetic relaxation at low temperatures through quantum tunneling and Raman mechanisms. Angle-resolved electron paramagnetic resonance (EPR) spectra on single crystals revealed signatures of low-dimensional magnetic behavior, which is solvatomorph-dependent, being the closest interdimer V···V separations (6.7-7.5 Å) much shorter than intramolecular V···V distances (11.9-12.1 Å). According to 1H diffusion ordered spectroscopy (DOSY) and EPR experiments, the complex adopts the desired monomeric structure in organic solution and its geometry was inferred from density functional theory (DFT) calculations. Spin relaxation measurements in a frozen toluene-d8/CD2Cl2 matrix yielded Tm values reaching 13 μs at 10 K, and coherent spin manipulations were demonstrated by Rabi nutation experiments at 70 K. The neutral quasi-macrocyclic structure, featuring nuclear spin-free donors and additional possibilities for chemical functionalization, makes 1' a new convenient spin-coherent building block in quantum technologies.
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Affiliation(s)
- Manuel Imperato
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università degli Studi di Modena e Reggio Emilia, via G. Campi 213/A, 41125 Modena, Italy
| | - Alessio Nicolini
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
| | - Matteo Boniburini
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
| | - Daniele Sartini
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy
| | - Enrico Benassi
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università degli Studi di Modena e Reggio Emilia, via G. Campi 213/A, 41125 Modena, Italy
| | - Mario Chiesa
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino, via P. Giuria 7, 10125 Torino, Italy
| | - Lara Gigli
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza (TS), Italy
| | - Yu-Kai Liao
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino, via P. Giuria 7, 10125 Torino, Italy
| | - Arsen Raza
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy
| | - Enrico Salvadori
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino, via P. Giuria 7, 10125 Torino, Italy
| | - Lorenzo Sorace
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze, via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy
| | - Andrea Cornia
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia, via G. Campi 103, 41125 Modena, Italy
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14
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He D, Zhang D, Yang L, Ye L, Xu RX, Zheng X. Unconventional Surface Doping Effect on the Spin State of an Adsorbed Magnetic Molecule. J Phys Chem Lett 2024; 15:4333-4341. [PMID: 38619466 DOI: 10.1021/acs.jpclett.4c00384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Magnetic molecules adsorbed on two-dimensional (2D) substrates have attracted broad attention because of their potential applications in quantum device applications. Experimental observations have demonstrated substantial alteration in the spin excitation energy of iron phthalocyanine (FePc) molecules when adsorbed on nitrogen-doped graphene substrates. However, the underlying mechanism responsible for this notable change remains unclear. To shed light on this, we employ an embedding method and ab initio quantum chemistry calculations to investigate the effects of surface doping on molecular properties. Our study unveils an unconventional chemical bonding at the interface between the FePc molecule and the N-doped graphene. This bonding interaction, stronger than non-covalent interactions, significantly modifies the magnetic anisotropy energy of the adsorbed molecule, consistent with experimental observations. These findings provide valuable insights into the electronic and magnetic properties of molecules on 2D substrates, offering a promising pathway for precise manipulation of molecular spin states.
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Affiliation(s)
- Dawei He
- Hefei National Research Center for Interdisciplinary Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Daochi Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Longqing Yang
- Hefei National Research Center for Interdisciplinary Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China
| | - Lyuzhou Ye
- Hefei National Research Center for Interdisciplinary Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Rui-Xue Xu
- Hefei National Research Center for Interdisciplinary Sciences at the Microscale & Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Xiao Zheng
- Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
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15
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Nain S, Mukhopadhyaya A, Ali ME. Unravelling the Highest Magnetic Anisotropy Among all the nd-Shells in [WCp2]0 Metallocene. Inorg Chem 2024; 63:7401-7411. [PMID: 38578709 DOI: 10.1021/acs.inorgchem.4c00437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Single-molecule magnets (SMMs) with a large magnetization reversal barrier are predominated by the lanthanide systems due to their strong spin-orbit coupling (SOC). However, the transition metals have also emerged as potential contenders and the largest magnetic anisotropy has been identified for a cobalt system among any d-series-based SMMs (Bunting et al. Science 2018, 362, eaat7319). In this work, we have explored the magnetic anisotropy in highly axial ligand field systems of metallocene, having different d-subshell (3d4, 4d4, and 5d4). The wave function-based multireference methods including static and dynamic electron correlations have been employed to investigate the zero-field splitting (ZFS) parameters. Here, we report exceptionally large magnetic anisotropy for a 5d complex of [WCp2]0 with the highest energy barrier that is nearly twice as high as the previous record value for the Co complex. We have also observed that the axial ZFS parameter (D) is increasing down the group in the order of 3d < 4d < 5d, pertaining to a large SOC.
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Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Aritra Mukhopadhyaya
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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16
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M Zahir FZ, Hay MA, Janetzki JT, Gable RW, Goerigk L, Boskovic C. Predicting valence tautomerism in diverse cobalt-dioxolene complexes: elucidation of the role of ligands and solvent. Chem Sci 2024; 15:5694-5710. [PMID: 38638213 PMCID: PMC11023039 DOI: 10.1039/d3sc04493a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 03/08/2024] [Indexed: 04/20/2024] Open
Abstract
The ability of molecular switches to reversibly interconvert between different forms promises potential applications at the scale of single molecules up to bulk materials. One type of molecular switch comprises cobalt-dioxolene compounds that exhibit thermally-induced valence tautomerism (VT) interconversions between low spin Co(iii)-catecholate (LS-CoIII-cat) and high spin Co(ii)-semiquinonate (HS-CoII-sq) forms. Two families of these compounds have been investigated for decades but have generally been considered separately: neutral [Co(diox)(sq)(N2L)] and cationic [Co(diox)(N4L)]+ complexes (diox = generic dioxolene, N2L/N4L = bidentate/tetradentate N-donor ancillary ligand). Computational identification of promising new candidate compounds prior to experimental exploration is beneficial for environmental and cost considerations but requires a thorough understanding of the underlying thermochemical parameters that influence the switching. Herein, we report a robust approach for the analysis of both cobalt-dioxolene families, which involved a quantitative density functional theory-based study benchmarked with reliable quasi-experimental references. The best-performing M06L-D4/def2-TZVPP level of theory has subsequently been verified by the synthesis and experimental investigation of three new complexes, two of which exhibit thermally-induced VT, while the third remains in the LS-CoIII-cat form across all temperatures, in agreement with prediction. Valence tautomerism in solution is markedly solvent-dependent, but the origin of this has not been definitively established. We have extended our computational approach to elucidate the correlation of VT transition temperature with solvent stabilisation energy and change in dipole moment. This new understanding may inform the development of VT compounds for applications in soft materials including films, gels, and polymers.
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Affiliation(s)
- F Zahra M Zahir
- School of Chemistry, University of Melbourne Victoria 3010 Australia
| | - Moya A Hay
- School of Chemistry, University of Melbourne Victoria 3010 Australia
| | - Jett T Janetzki
- School of Chemistry, University of Melbourne Victoria 3010 Australia
| | - Robert W Gable
- School of Chemistry, University of Melbourne Victoria 3010 Australia
| | - Lars Goerigk
- School of Chemistry, University of Melbourne Victoria 3010 Australia
| | - Colette Boskovic
- School of Chemistry, University of Melbourne Victoria 3010 Australia
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17
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Sturdza BK, Kong F, Yao X, Niu W, Ma J, Feng X, Riede MK, Bogani L, Nicholas RJ. Emissive brightening in molecular graphene nanoribbons by twilight states. Nat Commun 2024; 15:2985. [PMID: 38582761 PMCID: PMC10998898 DOI: 10.1038/s41467-024-47139-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 03/19/2024] [Indexed: 04/08/2024] Open
Abstract
Carbon nanomaterials are expected to be bright and efficient emitters, but structural disorder, intermolecular interactions and the intrinsic presence of dark states suppress their photoluminescence. Here, we study synthetically-made graphene nanoribbons with atomically precise edges and which are designed to suppress intermolecular interactions to demonstrate strong photoluminescence in both solutions and thin films. The resulting high spectral resolution reveals strong vibron-electron coupling from the radial-breathing-like mode of the ribbons. In addition, their cove-edge structure produces inter-valley mixing, which brightens conventionally-dark states to generate hitherto-unrecognised twilight states as predicted by theory. The coupling of these states to the nanoribbon phonon modes affects absorption and emission differently, suggesting a complex interaction with both Herzberg-Teller and Franck- Condon coupling present. Detailed understanding of the fundamental electronic processes governing the optical response will help the tailored chemical design of nanocarbon optical devices, via gap tuning and side-chain functionalisation.
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Affiliation(s)
- Bernd K Sturdza
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom.
| | - Fanmiao Kong
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, United Kingdom
| | - Xuelin Yao
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, United Kingdom
| | - Wenhui Niu
- Center for Advancing Electronics Dresden (CFAED), Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062, Dresden, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany
| | - Ji Ma
- Center for Advancing Electronics Dresden (CFAED), Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062, Dresden, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany
| | - Xinliang Feng
- Center for Advancing Electronics Dresden (CFAED), Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062, Dresden, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany
| | - Moritz K Riede
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - Lapo Bogani
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, United Kingdom.
- Departments of Chemistry and Physics, University of Florence, V. della Lastruccia, 50019, Sesto Fiorentino, Italy.
| | - Robin J Nicholas
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom.
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18
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Zhang Y, Oberg CP, Hu Y, Xu H, Yan M, Scholes GD, Wang M. Molecular and Supramolecular Materials: From Light-Harvesting to Quantum Information Science and Technology. J Phys Chem Lett 2024:3294-3316. [PMID: 38497707 DOI: 10.1021/acs.jpclett.4c00264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
The past two decades have witnessed immense advances in quantum information technology (QIT), benefited by advances in physics, chemistry, biology, and materials science and engineering. It is intriguing to consider whether these diverse molecular and supramolecular structures and materials, partially inspired by quantum effects as observed in sophisticated biological systems such as light-harvesting complexes in photosynthesis and the magnetic compass of migratory birds, might play a role in future QIT. If so, how? Herein, we review materials and specify the relationship between structures and quantum properties, and we identify the challenges and limitations that have restricted the intersection of QIT and chemical materials. Examples are broken down into two categories: materials for quantum sensing where nonclassical function is observed on the molecular scale and systems where nonclassical phenomena are present due to intermolecular interactions. We discuss challenges for materials chemistry and make comparisons to related systems found in nature. We conclude that if chemical materials become relevant for QIT, they will enable quite new kinds of properties and functions.
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Affiliation(s)
- Yipeng Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, P. R. China
| | - Catrina P Oberg
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Yue Hu
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Hongxue Xu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, P. R. China
| | - Mengwen Yan
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, P. R. China
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Mingfeng Wang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, P. R. China
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19
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Sasaki K, Abe E. Suppression of Pulsed Dynamic Nuclear Polarization by Many-Body Spin Dynamics. PHYSICAL REVIEW LETTERS 2024; 132:106904. [PMID: 38518331 DOI: 10.1103/physrevlett.132.106904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/06/2024] [Indexed: 03/24/2024]
Abstract
We study a mechanism by which nuclear hyperpolarization due to the polarization transfer from a microwave-pulse-controlled electron spin is suppressed. From analytical and numerical calculations of the unitary dynamics of multiple nuclear spins, we uncover that, combined with the formation of the dark state within a cluster of nuclei, coherent higher-order nuclear spin dynamics impose limits on the efficiency of the polarization transfer even in the absence of mundane depolarization processes such as nuclear spin diffusion and relaxation. Furthermore, we show that the influence of the dark state can be partly mitigated by introducing a disentangling operation. Our analysis is applied to the nuclear polarizations observed in ^{13}C nuclei coupled with a single nitrogen-vacancy center in diamond [Randall et al., Science 374, 1474 (2021)SCIEAS0036-807510.1126/science.abk0603]. Our Letter sheds light on collective engineering of nuclear spins as well as future designs of pulsed dynamic nuclear polarization protocols.
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Affiliation(s)
- Kento Sasaki
- Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Eisuke Abe
- RIKEN Center for Quantum Computing, Wako, Saitama 351-0198, Japan
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20
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Wanasinghe S, Gjoni A, Burson W, Majeski C, Zaslona B, Rury AS. Motional Narrowing through Photonic Exchange: Rational Suppression of Excitonic Disorder from Molecular Cavity Polariton Formation. J Phys Chem Lett 2024; 15:2405-2418. [PMID: 38394364 PMCID: PMC10926155 DOI: 10.1021/acs.jpclett.3c03217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024]
Abstract
Maximizing the coherence between the constituents of molecular materials remains a crucial goal toward the implementation of these systems into everyday optoelectronic technologies. Here we experimentally assess the ability of strong light-matter coupling in the collective limit to reduce energetic disorder using porphyrin-based chromophores in Fabry-Pérot (FP) microresonator structures. Following characterization of cavity polaritons formed from chemically distinct porphyrin dimers, we find that the peaks corresponding to the lower polariton (LP) state in each sample do not possess widths consistent with conventional theories. We model the behavior of the polariton peak widths effectively using the results of spectroscopic theory. We correlate differences in the suppression of excitonic energetic disorder between our samples with microscopic light-matter interactions and propose that the suppression stems from photonic exchange. Our results demonstrate that cavity polariton formation can suppress disorder and show researchers how to design coherence into hybrid molecular material systems.
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Affiliation(s)
- Sachithra
T. Wanasinghe
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
- Materials
Structural Dynamics Laboratory, Wayne State
University, Detroit, Michigan 48202, United
States
| | - Adelina Gjoni
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
- Materials
Structural Dynamics Laboratory, Wayne State
University, Detroit, Michigan 48202, United
States
| | - Wade Burson
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Caris Majeski
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Bradley Zaslona
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Aaron S. Rury
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
- Materials
Structural Dynamics Laboratory, Wayne State
University, Detroit, Michigan 48202, United
States
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21
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Kazmierczak NP, Lopez NE, Luedecke KM, Hadt RG. Determining the key vibrations for spin relaxation in ruffled Cu(ii) porphyrins via resonance Raman spectroscopy. Chem Sci 2024; 15:2380-2390. [PMID: 38362417 PMCID: PMC10866354 DOI: 10.1039/d3sc05774g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/12/2024] [Indexed: 02/17/2024] Open
Abstract
Pinpointing vibrational mode contributions to electron spin relaxation (T1) constitutes a key goal for developing molecular quantum bits (qubits) with long room-temperature coherence times. However, there remains no consensus to date as to the energy and symmetry of the relevant modes that drive relaxation. Here, we analyze a series of three geometrically-tunable S = ½ Cu(ii) porphyrins with varying degrees of ruffling distortion in the ground state. Theoretical calculations predict that increased distortion should activate low-energy ruffling modes (∼50 cm-1) for spin-phonon coupling, thereby causing faster spin relaxation in distorted porphyrins. However, experimental T1 times do not follow the degree of ruffling, with the highly distorted copper tetraisopropylporphyrin (CuTiPP) even displaying room-temperature coherence. Local mode fitting indicates that the true vibrations dominating T1 lie in the energy regime of bond stretches (∼200-300 cm-1), which are comparatively insensitive to the degree of ruffling. We employ resonance Raman (rR) spectroscopy to determine vibrational modes possessing both the correct energy and symmetry to drive spin-phonon coupling. The rR spectra uncover a set of mixed symmetric stretch vibrations from 200-250 cm-1 that explain the trends in temperature-dependent T1. These results indicate that molecular spin-phonon coupling models systematically overestimate the contribution of ultra-low-energy distortion modes to T1, pointing out a key deficiency of existing theory. Furthermore, this work highlights the untapped power of rR spectroscopy as a tool for building spin dynamics structure-property relationships in molecular quantum information science.
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Affiliation(s)
- Nathanael P Kazmierczak
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology Pasadena California 91125 USA
| | - Nathan E Lopez
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology Pasadena California 91125 USA
| | - Kaitlin M Luedecke
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology Pasadena California 91125 USA
| | - Ryan G Hadt
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology Pasadena California 91125 USA
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22
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Chiesa A, Santini P, Garlatti E, Luis F, Carretta S. Molecular nanomagnets: a viable path toward quantum information processing? REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:034501. [PMID: 38314645 DOI: 10.1088/1361-6633/ad1f81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 01/17/2024] [Indexed: 02/06/2024]
Abstract
Molecular nanomagnets (MNMs), molecules containing interacting spins, have been a playground for quantum mechanics. They are characterized by many accessible low-energy levels that can be exploited to store and process quantum information. This naturally opens the possibility of using them as qudits, thus enlarging the tools of quantum logic with respect to qubit-based architectures. These additional degrees of freedom recently prompted the proposal for encoding qubits with embedded quantum error correction (QEC) in single molecules. QEC is the holy grail of quantum computing and this qudit approach could circumvent the large overhead of physical qubits typical of standard multi-qubit codes. Another important strength of the molecular approach is the extremely high degree of control achieved in preparing complex supramolecular structures where individual qudits are linked preserving their individual properties and coherence. This is particularly relevant for building quantum simulators, controllable systems able to mimic the dynamics of other quantum objects. The use of MNMs for quantum information processing is a rapidly evolving field which still requires to be fully experimentally explored. The key issues to be settled are related to scaling up the number of qudits/qubits and their individual addressing. Several promising possibilities are being intensively explored, ranging from the use of single-molecule transistors or superconducting devices to optical readout techniques. Moreover, new tools from chemistry could be also at hand, like the chiral-induced spin selectivity. In this paper, we will review the present status of this interdisciplinary research field, discuss the open challenges and envisioned solution paths which could finally unleash the very large potential of molecular spins for quantum technologies.
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Affiliation(s)
- A Chiesa
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - P Santini
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - E Garlatti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - F Luis
- Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC, Universidad de Zaragoza, Zaragoza, Spain
- Departamento de Fısica de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - S Carretta
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
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23
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Medagedara H, Teferi MY, Wanasinghe ST, Burson W, Kizi S, Zaslona B, Mardis KL, Niklas J, Poluektov OG, Rury AS. Decorrelated singlet and triplet exciton delocalization in acetylene-bridged Zn-porphyrin dimers. Chem Sci 2024; 15:1736-1751. [PMID: 38303928 PMCID: PMC10829018 DOI: 10.1039/d3sc03327a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/12/2023] [Indexed: 02/03/2024] Open
Abstract
The controlled delocalization of molecular excitons remains an important goal towards the application of organic chromophores in processes ranging from light-initiated chemical transformations to classical and quantum information processing. In this study, we present a methodology to couple optical and magnetic spectroscopic techniques and assess the delocalization of singlet and triplet excitons in model molecular chromophores. By comparing the steady-state and time-resolved optical spectra of Zn-porphyrin monomers and weakly coupled dimers, we show that we can use the identity of substituents bound at specific positions of the macromolecules' rings to control the inter-ring delocalization of singlet excitons stemming from their B states through acetylene bridges. While broadened steady-state absorption spectra suggest the presence of delocalized B state excitons in mesityl-substituted Zn-tetraphenyl porphyrin dimers (Zn2U-D), we confirm this conclusion by measuring an enhanced ultrafast non-radiative relaxation from these inter-ring excitonic states to lower lying electronic states relative to their monomer. In contrast to the delocalized nature of singlet excitons, we use time-resolved EPR and ENDOR spectroscopies to show that the triplet states of the Zn-porphyrin dimers remain localized on one of the two macrocyclic sub-units. We use the analysis of EPR and ENDOR measurements on unmetallated model porphyrin monomers and dimers to support this conclusion. The results of DFT calculations also support the interpretation of localized triplet states. These results demonstrate researchers cannot conclude triplet excitons delocalize in macromolecular based on the presence of spatially extended singlet excitons, which can help in the design of chromophores for application in spin conversion and information processing technologies.
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Affiliation(s)
- Hasini Medagedara
- Department of Chemistry, Wayne State University Detroit MI 48202 USA
| | - Mandefro Y Teferi
- Chemical Sciences and Engineering Division, Argonne National Laboratory Lemont IL 60439 USA
| | | | - Wade Burson
- Department of Chemistry, Wayne State University Detroit MI 48202 USA
| | - Shahad Kizi
- Department of Chemistry, Wayne State University Detroit MI 48202 USA
| | - Bradly Zaslona
- Department of Chemistry, Wayne State University Detroit MI 48202 USA
| | - Kristy L Mardis
- Department of Chemistry, Physics, and Engineering Sciences, Chicago State University Chicago IL 60628 USA
| | - Jens Niklas
- Chemical Sciences and Engineering Division, Argonne National Laboratory Lemont IL 60439 USA
| | - Oleg G Poluektov
- Chemical Sciences and Engineering Division, Argonne National Laboratory Lemont IL 60439 USA
| | - Aaron S Rury
- Department of Chemistry, Wayne State University Detroit MI 48202 USA
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24
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Wojnar MK, Kundu K, Kairalapova A, Wang X, Ozarowski A, Berkelbach TC, Hill S, Freedman DE. Ligand field design enables quantum manipulation of spins in Ni 2+ complexes. Chem Sci 2024; 15:1374-1383. [PMID: 38274078 PMCID: PMC10806831 DOI: 10.1039/d3sc04919a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/02/2023] [Indexed: 01/27/2024] Open
Abstract
Creating the next generation of quantum systems requires control and tunability, which are key features of molecules. To design these systems, one must consider the ground-state and excited-state manifolds. One class of systems with promise for quantum sensing applications, which require water solubility, are d8 Ni2+ ions in octahedral symmetry. Yet, most Ni2+ complexes feature large zero-field splitting, precluding manipulation by commercial microwave sources due to the relatively large spin-orbit coupling constant of Ni2+ (630 cm-1). Since low lying excited states also influence axial zero-field splitting, D, a combination of strong field ligands and rigidly held octahedral symmetry can ameliorate these challenges. Towards these ends, we performed a theoretical and computational analysis of the electronic and magnetic structure of a molecular qubit, focusing on the impact of ligand field strength on D. Based on those results, we synthesized 1, [Ni(ttcn)2](BF4)2 (ttcn = 1,4,7-trithiacyclononane), which we computationally predict will have a small D (Dcalc = +1.15 cm-1). High-field high-frequency electron paramagnetic resonance (EPR) data yield spin Hamiltonian parameters: gx = 2.1018(15), gx = 2.1079(15), gx = 2.0964(14), D = +0.555(8) cm-1 and E = +0.072(5) cm-1, which confirm the expected weak zero-field splitting. Dilution of 1 in the diamagnetic Zn analogue, [Ni0.01Zn0.99(ttcn)2](BF4)2 (1') led to a slight increase in D to ∼0.9 cm-1. The design criteria in minimizing D in 1via combined computational and experimental methods demonstrates a path forward for EPR and optical addressability of a general class of S = 1 spins.
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Affiliation(s)
- Michael K Wojnar
- Department of Chemistry, Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
| | - Krishnendu Kundu
- National High Magnetic Field Laboratory Tallahassee Florida 32310 USA
| | | | - Xiaoling Wang
- National High Magnetic Field Laboratory Tallahassee Florida 32310 USA
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory Tallahassee Florida 32310 USA
| | | | - Stephen Hill
- National High Magnetic Field Laboratory Tallahassee Florida 32310 USA
- Department of Physics, Florida State University Florida 32306 USA
| | - Danna E Freedman
- Department of Chemistry, Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
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25
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Palmer JR, Williams ML, Young RM, Peinkofer KR, Phelan BT, Krzyaniak MD, Wasielewski MR. Oriented Triplet Excitons as Long-Lived Electron Spin Qutrits in a Molecular Donor-Acceptor Single Cocrystal. J Am Chem Soc 2024; 146:1089-1099. [PMID: 38156609 DOI: 10.1021/jacs.3c12277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The photogeneration of multiple unpaired electron spins within molecules is a promising route to applications in quantum information science because they can be initialized into well-defined, multilevel quantum states (S > 1/2) and reproducibly fabricated by chemical synthesis. However, coherent manipulation of these spin states is difficult to realize in typical molecular systems due to the lack of selective addressability and short coherence times of the spin transitions. Here, these challenges are addressed by using donor-acceptor single cocrystals composed of pyrene and naphthalene dianhydride to host spatially oriented triplet excitons, which exhibit promising photogenerated qutrit properties. Time-resolved electron paramagnetic resonance (TREPR) spectroscopy demonstrates that spatially orienting triplet excitons in a single crystal platform imparts narrow, well-resolved, tunable resonances in the triplet EPR spectrum, allowing selective addressability of the spin sublevel transitions. Pulse-EPR spectroscopy reveals that at temperatures above 30 K, spin decoherence of these triplet excitons is driven by exciton diffusion. However, coherence is limited by electronic spin dipolar coupling below 30 K, where T2 varies nonlinearly with the optical excitation density due to exciton annihilation. Overall, an optimized coherence time of T2 = 7.1 μs at 20 K is achieved. These results provide important insights into designing solid-state molecular excitonic materials with improved spin qutrit properties.
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Affiliation(s)
- Jonathan R Palmer
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Malik L Williams
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Ryan M Young
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Kathryn R Peinkofer
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Brian T Phelan
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Matthew D Krzyaniak
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
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26
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Mariano L, Mondal S, Lunghi A. Spin-Vibronic Dynamics in Open-Shell Systems beyond the Spin Hamiltonian Formalism. J Chem Theory Comput 2024; 20:323-332. [PMID: 38153836 PMCID: PMC10782446 DOI: 10.1021/acs.jctc.3c01130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/30/2023]
Abstract
Vibronic coupling has a dramatic influence over a large number of molecular processes, ranging from photochemistry to spin relaxation and electronic transport. The simulation of vibronic coupling with multireference wave function methods has been largely applied to organic compounds, and only early efforts are available for open-shell systems such as transition metal and lanthanide complexes. In this work, we derive a numerical strategy to differentiate the molecular electronic Hamiltonian in the context of multireference ab initio methods and inclusive of spin-orbit coupling effects. We then provide a formulation of open quantum system dynamics able to predict the time evolution of the electron density matrix under the influence of a Markovian phonon bath up to fourth-order perturbation theory. We apply our method to Co(II) and Dy(III) molecular complexes exhibiting long spin relaxation times and successfully validate our strategy against the use of an effective spin Hamiltonian. Our study sheds light on the nature of vibronic coupling, the importance of electronic excited states in spin relaxation, and the need for high-level computational chemistry to quantify it.
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Affiliation(s)
- Lorenzo
A. Mariano
- School of Physics, AMBER and CRANN
Institute, Trinity College, Dublin 2, Ireland
| | - Sourav Mondal
- School of Physics, AMBER and CRANN
Institute, Trinity College, Dublin 2, Ireland
| | - Alessandro Lunghi
- School of Physics, AMBER and CRANN
Institute, Trinity College, Dublin 2, Ireland
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27
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Yamauchi A, Tanaka K, Fuki M, Fujiwara S, Kimizuka N, Ryu T, Saigo M, Onda K, Kusumoto R, Ueno N, Sato H, Kobori Y, Miyata K, Yanai N. Room-temperature quantum coherence of entangled multiexcitons in a metal-organic framework. SCIENCE ADVANCES 2024; 10:eadi3147. [PMID: 38170775 PMCID: PMC10775993 DOI: 10.1126/sciadv.adi3147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024]
Abstract
Singlet fission can generate an exchange-coupled quintet triplet pair state 5TT, which could lead to the realization of quantum computing and quantum sensing using entangled multiple qubits even at room temperature. However, the observation of the quantum coherence of 5TT has been limited to cryogenic temperatures, and the fundamental question is what kind of material design will enable its room-temperature quantum coherence. Here, we show that the quantum coherence of singlet fission-derived 5TT in a chromophore-integrated metal-organic framework can be over hundred nanoseconds at room temperature. The suppressed motion of the chromophores in ordered domains within the metal-organic framework leads to the enough fluctuation of the exchange interaction necessary for 5TT generation but, at the same time, does not cause severe 5TT decoherence. Furthermore, the phase and amplitude of quantum beating depend on the molecular motion, opening the way to room-temperature molecular quantum computing based on multiple quantum gate control.
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Affiliation(s)
- Akio Yamauchi
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kentaro Tanaka
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masaaki Fuki
- Molecular Photoscience Research Center, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
- CREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
| | - Saiya Fujiwara
- RIKEN, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
| | - Nobuo Kimizuka
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
- Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tomohiro Ryu
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masaki Saigo
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ken Onda
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryota Kusumoto
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Nami Ueno
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, Japan
| | - Harumi Sato
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, Japan
| | - Yasuhiro Kobori
- Molecular Photoscience Research Center, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
- CREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
| | - Kiyoshi Miyata
- CREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Nobuhiro Yanai
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
- CREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
- Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
- FOREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
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28
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Reid OG, Johnson JC, Eaves JD, Damrauer NH, Anthony JE. Molecular Control of Triplet-Pair Spin Polarization and Its Optoelectronic Magnetic Resonance Probes. Acc Chem Res 2024; 57:59-69. [PMID: 38103045 PMCID: PMC10765369 DOI: 10.1021/acs.accounts.3c00556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023]
Abstract
ConspectusPreparing and manipulating pure magnetic states in molecular systems are the key initial requirements for harnessing the power of synthetic chemistry to drive practical quantum sensing and computing technologies. One route for achieving the requisite higher spin states in organic systems exploits the phenomenon of singlet fission, which produces pairs of triplet excited states from initially photoexcited singlets in molecular assemblies with multiple chromophores. The resulting spin states are characterized by total spin (quintet, triplet, or singlet) and its projection onto a specified molecular or magnetic field axis. These excited states are typically highly polarized but exhibit an impure spin population pattern. Herein, we report the prediction and experimental verification of molecular design rules that drive the population of a single pure magnetic state and describe the progress toward its experimental realization.A vital feature of this work is the close partnership among theory, chemical synthesis, and spectroscopy. We begin by presenting our theoretical framework for understanding spin manifold interconversion in singlet fission systems. This theory makes specific testable predictions about the intermolecular structure and orientation relative to an external magnetic field that should lead to pure magnetic state preparation and provides a powerful tool for interpreting magnetic spectra. We then test these predictions through detailed magnetic spectroscopy experiments on a series of new molecular architectures that meet one or more of the identified structural criteria. Many of these architectures rely on the synthesis of molecules with features unique to this effort: rigid bridges between chromophores in dimers, heteroacenes with tailored singlet/triplet-pair energy level matching, or side-group engineering to produce specific crystal structures. The spin evolution of these systems is revealed through our application and development of several magnetic resonance methods, each of which has different sensitivities and relevance in environments relevant to quantum applications.Our theoretical predictions prove to be remarkably consistent with our experimental results, though experimentally meeting all the structural prescriptions demanded by theory for true pure-state preparation remains a challenge. Our magnetic spectra agree with our model of triplet-pair behavior, including funneling of the population to the ms = 0 magnetic sublevel of the quintet under specified conditions in dimers and crystals, showing that this phenomenon is subject to control through molecular design. Moreover, our demonstration of novel and/or highly sensitive detection mechanisms of spin states in singlet fission systems, including photoluminescence (PL), photoinduced absorption (PA), and magnetoconductance (MC), points the way toward both a deeper understanding of how these systems evolve and technologically feasible routes toward experiments at the single-molecule quantum limit that are desirable for computational applications.
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Affiliation(s)
- Obadiah G. Reid
- National
Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, Boulder, Colorado 80309, United States
| | - Justin C. Johnson
- National
Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, Boulder, Colorado 80309, United States
| | - Joel D. Eaves
- Renewable
and Sustainable Energy Institute, Boulder, Colorado 80309, United States
- Department
of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Niels H. Damrauer
- Renewable
and Sustainable Energy Institute, Boulder, Colorado 80309, United States
- Department
of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - John E. Anthony
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
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29
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Imperato M, Nicolini A, Borsari M, Briganti M, Chiesa M, Liao YK, Ranieri A, Raza A, Salvadori E, Sorace L, Cornia A. Quantum spin coherence and electron spin distribution channels in vanadyl-containing lantern complexes. Inorg Chem Front 2023; 11:186-195. [PMID: 38221947 PMCID: PMC10782212 DOI: 10.1039/d3qi01806g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/02/2023] [Indexed: 01/16/2024]
Abstract
We herein investigate the heterobimetallic lantern complexes [PtVO(SOCR)4] as charge neutral electronic qubits based on vanadyl complexes (S = 1/2) with nuclear spin-free donor atoms. The derivatives with R = Me (1) and Ph (2) give highly resolved X-band EPR spectra in frozen CH2Cl2/toluene solution, which evidence the usual hyperfine coupling with the 51V nucleus (I = 7/2) and an additional superhyperfine interaction with the I = 1/2 nucleus of the 195Pt isotope (natural abundance ca. 34%). DFT calculations ascribe the spin density delocalization on the Pt2+ ion to a combination of π and δ pathways, with the former representing the predominant channel. Spin relaxation measurements in frozen CD2Cl2/toluene-d8 solution between 90 and 10 K yield Tm values (1-6 μs in 1 and 2-11 μs in 2) which compare favorably with those of known vanadyl-based qubits in similar matrices. Coherent spin manipulations indeed prove possible at 70 K, as shown by the observation of Rabi oscillations in nutation experiments. The results indicate that the heavy Group 10 metal ion is not detrimental to the coherence properties of the vanadyl moiety and that Pt-VO lanterns can be used as robust spin-coherent building blocks in materials science and quantum technologies.
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Affiliation(s)
- Manuel Imperato
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia via G. Campi 103 41125 Modena Italy
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università degli Studi di Modena e Reggio Emilia via G. Campi 213/A 41125 Modena Italy
| | - Alessio Nicolini
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia via G. Campi 103 41125 Modena Italy
| | - Marco Borsari
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia via G. Campi 103 41125 Modena Italy
| | - Matteo Briganti
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze via della Lastruccia 3 50019 Sesto Fiorentino FI Italy
| | - Mario Chiesa
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino via P. Giuria 7 10125 Torino Italy
| | - Yu-Kai Liao
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino via P. Giuria 7 10125 Torino Italy
| | - Antonio Ranieri
- Dipartimento di Scienze della Vita, Università degli Studi di Modena e Reggio Emilia via G. Campi 103 41125 Modena Italy
| | - Arsen Raza
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze via della Lastruccia 3 50019 Sesto Fiorentino FI Italy
| | - Enrico Salvadori
- Dipartimento di Chimica e NIS Centre, Università degli Studi di Torino via P. Giuria 7 10125 Torino Italy
| | - Lorenzo Sorace
- Dipartimento di Chimica "Ugo Schiff" e UdR INSTM, Università degli Studi di Firenze via della Lastruccia 3 50019 Sesto Fiorentino FI Italy
| | - Andrea Cornia
- Dipartimento di Scienze Chimiche e Geologiche e UdR INSTM, Università degli Studi di Modena e Reggio Emilia via G. Campi 103 41125 Modena Italy
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30
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Orihashi K, Yamauchi A, Fujiwara S, Asada M, Nakamura T, Ka-Ho Hui J, Kimizuka N, Tateishi K, Uesaka T, Yanai N. Spin-Polarized Radicals with Extremely Long Spin-Lattice Relaxation Time at Room Temperature in a Metal-Organic Framework. J Am Chem Soc 2023; 145:27650-27656. [PMID: 38079364 DOI: 10.1021/jacs.3c09563] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The generation of spin polarization is key in quantum information science and dynamic nuclear polarization. Polarized electron spins with long spin-lattice relaxation times (T1) at room temperature are important for these applications but have been difficult to achieve. We report the realization of spin-polarized radicals with extremely long T1 at room temperature in a metal-organic framework (MOF) in which azaacene chromophores are densely integrated. Persistent radicals are generated in the MOF by charge separation after photoexcitation. Spin polarization of a triplet generated by photoexcitation is successfully transferred to the persistent radicals. Pulse electron spin resonance measurements reveal that the T1 of the polarized radical in the MOF is as long as 214 μs with a relatively long spin-spin relaxation time T2 of the radicals of up to 0.98 μs at room temperature. The achievement of extremely long spin polarization in MOFs with nanopores accessible to guest molecules will be an important cornerstone for future highly sensitive quantum sensing and efficient dynamic nuclear polarization.
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Affiliation(s)
- Kana Orihashi
- Department of Applied Chemistry, Graduate School of Engineering and Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Akio Yamauchi
- Department of Applied Chemistry, Graduate School of Engineering and Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Saiya Fujiwara
- RIKEN Center for Emergent Matter Science, Riken, Wako, Saitama 351-0198, Japan
| | - Mizue Asada
- Institute for Molecular Science, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan
| | - Toshikazu Nakamura
- Institute for Molecular Science, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan
| | - Joseph Ka-Ho Hui
- Department of Applied Chemistry, Graduate School of Engineering and Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Nobuo Kimizuka
- Department of Applied Chemistry, Graduate School of Engineering and Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kenichiro Tateishi
- Cluster for Pioneering Research, Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tomohiro Uesaka
- Cluster for Pioneering Research, Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Nobuhiro Yanai
- Department of Applied Chemistry, Graduate School of Engineering and Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
- FOREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
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31
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Bindra JK, Niklas J, Jeong Y, Jasper AW, Kretzschmar M, Kern J, Utschig LM, Poluektov OG. Coherences of Photoinduced Electron Spin Qubit Pair States in Photosystem I. J Phys Chem B 2023; 127:10108-10117. [PMID: 37980604 DOI: 10.1021/acs.jpcb.3c06658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
This publication presents the first comprehensive experimental study of electron spin coherences in photosynthetic reaction center proteins, specifically focusing on photosystem I (PSI). The ultrafast electron transfer in PSI generates spin-correlated radical pairs (SCRPs), which are entangled spin pairs formed in well-defined spin states (Bell states). Since their discovery in our group in the 1980s, SCRPs have been extensively used to enhance our understanding of structure-function relationships in photosynthetic proteins. More recently, SCRPs have been utilized as tools for quantum sensing. Electron spin decoherence poses a significant challenge in realizing practical applications of electron spin qubits, particularly the creation of quantum entanglement between multiple electron spins. This work is focused on the systematic characterization of decoherence in SCRPs of PSI. These decoherence times were measured as electron spin echo decay times, termed phase memory times (TM), at various temperatures. Decoherence was recorded on both transient SCRP states P700+A1- and thermalized states. Our study reveals that TM exhibits minimal dependence on the biological species, biochemical treatment, and paramagnetic species. The analysis indicates that nuclear spin diffusion and instantaneous diffusion mechanisms alone cannot explain the observed decoherence. As a plausible explanation we discuss the assumption that the low-temperature dynamics of methyl groups in the protein surrounding the unpaired electron spin centers is the main factor governing the loss of the spin coherence in PSI.
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Affiliation(s)
- Jasleen K Bindra
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Jens Niklas
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Yeonjun Jeong
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Ahren W Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Moritz Kretzschmar
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Lisa M Utschig
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Oleg G Poluektov
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
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32
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Qiu Y, Eckvahl HJ, Equbal A, Krzyaniak MD, Wasielewski MR. Enhancing Coherence Times of Chromophore-Radical Molecular Qubits and Qudits by Rational Design. J Am Chem Soc 2023; 145:25903-25909. [PMID: 37963349 DOI: 10.1021/jacs.3c10772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
An important criterion for quantum operations is long qubit coherence times. To elucidate the influence of molecular structure on the coherence times of molecular spin qubits and qudits, a series of molecules featuring perylenediimide (PDI) chromophores covalently linked to stable nitroxide radicals were synthesized and investigated by pulse electron paramagnetic resonance spectroscopy. Photoexcitation of PDI in these systems creates an excited quartet state (Q) followed by a spin-polarized doublet ground state (D0), which hold promise as spin qudits and qubits, respectively. By tailoring the molecular structure of these spin qudit/qubit candidates by selective deuteration and eliminating intramolecular motion, coherence times of Tm = 9.1 ± 0.3 and 4.2 ± 0.3 μs at 85 K for D0 and Q, respectively, are achieved. These coherence times represent a nearly 3-fold enhancement compared to those of the initial molecular design. This approach offers a rational structural design protocol for effectively extending coherence times in molecular spin qudits/qubits.
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Affiliation(s)
- Yunfan Qiu
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3313, United States
| | - Hannah J Eckvahl
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3313, United States
| | - Asif Equbal
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3313, United States
| | - Matthew D Krzyaniak
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3313, United States
| | - Michael R Wasielewski
- Department of Chemistry, Center for Molecular Quantum Transduction, and Paula M. Trienens Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3313, United States
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33
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Kitzmann WR, Hunger D, Reponen APM, Förster C, Schoch R, Bauer M, Feldmann S, van Slageren J, Heinze K. Electronic Structure and Excited-State Dynamics of the NIR-II Emissive Molybdenum(III) Analogue to the Molecular Ruby. Inorg Chem 2023; 62:15797-15808. [PMID: 37718553 DOI: 10.1021/acs.inorgchem.3c02186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Photoactive chromium(III) complexes saw a conceptual breakthrough with the discovery of the prototypical molecular ruby mer-[Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine), which shows intense long-lived near-infrared (NIR) phosphorescence from metal-centered spin-flip states. In contrast to the numerous studies on chromium(III) photophysics, only 10 luminescent molybdenum(III) complexes have been reported so far. Here, we present the synthesis and characterization of mer-MoX3(ddpd) (1, X = Cl; 2, X = Br) and cisfac-[Mo(ddpd)2]3+ (cisfac-[3]3+), an isomeric heavy homologue of the prototypical molecular ruby. For cisfac-[3]3+, we found strong zero-field splitting using magnetic susceptibility measurements and electron paramagnetic resonance spectroscopy. Electronic spectra covering the spin-forbidden transitions show that the spin-flip states in mer-1, mer-2, and cisfac-[3]3+ are much lower in energy than those in comparable chromium(III) compounds. While all three complexes show weak spin-flip phosphorescence in NIR-II, the emission of cisfac-[3]3+ peaking at 1550 nm is particularly low in energy. Femtosecond transient absorption spectroscopy reveals a short excited-state lifetime of 1.4 ns, 6 orders of magnitude shorter than that of mer-[Cr(ddpd)2]3+. Using density functional theory and ab initio multireference calculations, we break down the reasons for this disparity and derive principles for the design of future stable photoactive molybdenum(III) complexes.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - David Hunger
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Antti-Pekka M Reponen
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Roland Schoch
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Sascha Feldmann
- Rowland Institute, Harvard University, 100 Edwin H. Land Boulevard, Cambridge, Massachusetts 02142, United States
| | - Joris van Slageren
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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34
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Miller EG, Singh M, Parkin S, Sammakia T, Damrauer NH. Preparation of a Rigid and Nearly Coplanar Bis-tetracene Dimer through an Application of the CANAL Reaction. J Org Chem 2023; 88:12251-12256. [PMID: 37607040 DOI: 10.1021/acs.joc.3c00809] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
A rigid tetracene dimer with a substantial interchromophore distance has been prepared through an application of the recently developed catalytic arene-norbornene annulation (CANAL) reaction. An iterative cycloaddition route was found to be unsuccessful, so a shorter route was adopted whereby fragments were coupled in the penultimate step to form a 13:1 mixture of two diastereomers, the major of which was isolated and crystallized. Constituent tetracene moieties are linked with a rigid, well-defined bridge and feature a near-co-planar mutual orientation of the acenes.
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Affiliation(s)
- Ethan G Miller
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Madhu Singh
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Tarek Sammakia
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Niels H Damrauer
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
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35
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Kazmierczak NP, Luedecke KM, Gallmeier ET, Hadt RG. T1 Anisotropy Elucidates Spin Relaxation Mechanisms in an S = 1 Cr(IV) Optically Addressable Molecular Qubit. J Phys Chem Lett 2023; 14:7658-7664. [PMID: 37603791 DOI: 10.1021/acs.jpclett.3c01964] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Paramagnetic molecules offer unique advantages for quantum information science owing to their spatial compactness, synthetic tunability, room-temperature quantum coherence, and potential for optical state initialization and readout. However, current optically addressable molecular qubits are hampered by rapid spin-lattice relaxation (T1) even at sub-liquid nitrogen temperatures. Here, we use temperature- and orientation-dependent pulsed electron paramagnetic resonance (EPR) to elucidate the negative sign of the ground state zero-field splitting (ZFS) and assign T1 anisotropy to specific types of motion in an optically addressable S = 1 Cr(o-tolyl)4 molecular qubit. The anisotropy displays a distinct sin2(2θ) functional form that is not observed in S = 1/2 Cu(acac)2 or other Cu(II)/V(IV) microwave addressable molecular qubits. The Cr(o-tolyl)4 T1 anisotropy is ascribed to couplings between electron spins and rotational motion in low-energy acoustic or pseudoacoustic phonons. Our findings suggest that rotational degrees of freedom should be suppressed to maximize the coherence temperature of optically addressable qubits.
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Affiliation(s)
- Nathanael P Kazmierczak
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Kaitlin M Luedecke
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Elisabeth T Gallmeier
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
| | - Ryan G Hadt
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, United States
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36
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Jackson BA, Khan SN, Miliordos E. A fresh perspective on metal ammonia molecular complexes and expanded metals: opportunities in catalysis and quantum information. Chem Commun (Camb) 2023; 59:10572-10587. [PMID: 37555315 DOI: 10.1039/d3cc02956e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Recent advances in our comprehension of the electronic structure of metal ammonia complexes have opened avenues for novel materials with diffuse electrons. These complexes in their ground state can host peripheral "Rydberg" electrons which populate a hydrogenic-type shell model imitating atoms. Aggregates of such complexes form the so-called expanded or liquid metals. Expanded metals composed of d- and f-block metal ammonia complexes offer properties, such as magnetic moments and larger numbers of diffuse electrons, not present for alkali and alkaline earth (s-block) metals. In addition, tethering metal ammonia complexes via hydrocarbon chains (replacement of ammonia ligands with diamines) yields materials that can be used for redox catalysis and quantum computing, sensing, and optics. This perspective summarizes the recent findings for gas-phase isolated metal ammonia complexes and projects the obtained knowledge to the condensed phase regime. Possible applications for the newly introduced expanded metals and linked solvated electrons precursors are discussed and future directions are proposed.
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Affiliation(s)
- Benjamin A Jackson
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
| | - Shahriar N Khan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
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37
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Schlimgen AW, Guo Y, Head-Marsden K. Characterizing Excited States of a Copper-Based Molecular Qubit Candidate with Correlated Electronic Structure Methods. J Phys Chem A 2023; 127:6764-6770. [PMID: 37531508 DOI: 10.1021/acs.jpca.3c03827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Molecular spins have a variety of potential advantages as qubits for quantum computation, such as tunability and well-understood design pathways through organometallic synthesis. Organometallic and heavy-metal-based molecular spin qubits can also exhibit rich electronic structures due to ligand field interactions and electron correlation. These features make consistent and reliable modeling of these species a considerable challenge for contemporary electronic structure techniques. Here, we elucidate the electronic structure of a Cu(II) complex analogous to a recently proposed room-temperature molecular spin qubit. Using active space methods to describe the electron correlation, we show the nuanced interaction between the metal d orbitals and ligand σ and π orbitals makes these systems challenging to model, both in terms of the delocalized spin density and the excited state ordering. We show that predicting the correct spin delocalization requires special consideration of the Cu d orbitals and that the excited state spectrum for the Cu(III) complex also requires the explicit inclusion of the π orbitals in the active space. These interactions are rather common in molecular spin qubit motifs and may play an important role in spin-decoherence processes. Our results may lend insight into future studies of the orbital interactions and electron delocalization of similar complexes.
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Affiliation(s)
- Anthony W Schlimgen
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 61630, United States
| | - Yangyang Guo
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 61630, United States
| | - Kade Head-Marsden
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 61630, United States
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38
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Gorgon S, Lv K, Grüne J, Drummond BH, Myers WK, Londi G, Ricci G, Valverde D, Tonnelé C, Murto P, Romanov AS, Casanova D, Dyakonov V, Sperlich A, Beljonne D, Olivier Y, Li F, Friend RH, Evans EW. Reversible spin-optical interface in luminescent organic radicals. Nature 2023; 620:538-544. [PMID: 37587296 PMCID: PMC10432275 DOI: 10.1038/s41586-023-06222-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 05/16/2023] [Indexed: 08/18/2023]
Abstract
Molecules present a versatile platform for quantum information science1,2 and are candidates for sensing and computation applications3,4. Robust spin-optical interfaces are key to harnessing the quantum resources of materials5. To date, carbon-based candidates have been non-luminescent6,7, which prevents optical readout via emission. Here we report organic molecules showing both efficient luminescence and near-unity generation yield of excited states with spin multiplicity S > 1. This was achieved by designing an energy resonance between emissive doublet and triplet levels, here on covalently coupled tris(2,4,6-trichlorophenyl) methyl-carbazole radicals and anthracene. We observed that the doublet photoexcitation delocalized onto the linked acene within a few picoseconds and subsequently evolved to a pure high-spin state (quartet for monoradical, quintet for biradical) of mixed radical-triplet character near 1.8 eV. These high-spin states are coherently addressable with microwaves even at 295 K, with optical readout enabled by reverse intersystem crossing to emissive states. Furthermore, for the biradical, on return to the ground state the previously uncorrelated radical spins either side of the anthracene shows strong spin correlation. Our approach simultaneously supports a high efficiency of initialization, spin manipulations and light-based readout at room temperature. The integration of luminescence and high-spin states creates an organic materials platform for emerging quantum technologies.
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Affiliation(s)
- Sebastian Gorgon
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford, UK.
| | - Kuo Lv
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | - Jeannine Grüne
- Experimental Physics VI, Faculty of Physics and Astronomy, University of Würzburg, Würzburg, Germany
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - William K Myers
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, Oxford, UK
| | - Giacomo Londi
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | - Gaetano Ricci
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | - Danillo Valverde
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | | | - Petri Murto
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | | | - Vladimir Dyakonov
- Experimental Physics VI, Faculty of Physics and Astronomy, University of Würzburg, Würzburg, Germany
| | - Andreas Sperlich
- Experimental Physics VI, Faculty of Physics and Astronomy, University of Würzburg, Würzburg, Germany
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium
| | - Yoann Olivier
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, P. R. China
| | | | - Emrys W Evans
- Department of Chemistry, Swansea University, Swansea, UK.
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39
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Beatrez W, Pillai A, Janes O, Suter D, Ajoy A. Electron Induced Nanoscale Nuclear Spin Relaxation Probed by Hyperpolarization Injection. PHYSICAL REVIEW LETTERS 2023; 131:010802. [PMID: 37478433 DOI: 10.1103/physrevlett.131.010802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 06/07/2023] [Indexed: 07/23/2023]
Abstract
We report on experiments that quantify the role of a central electronic spin as a relaxation source for nuclear spins in its nanoscale environment. Our strategy exploits hyperpolarization injection from the electron as a means to controllably probe an increasing number of nuclear spins in the bath and subsequently interrogate them with high fidelity. Our experiments are focused on a model system of a nitrogen vacancy center electronic spin surrounded by several hundred ^{13}C nuclear spins. We observe that the ^{13}C transverse spin relaxation times vary significantly with the extent of hyperpolarization injection, allowing the ability to measure the influence of electron-mediated relaxation extending over several nanometers. These results suggest interesting new means to spatially discriminate nuclear spins in a nanoscale environment and have direct relevance to dynamic nuclear polarization and quantum sensors and memories constructed from hyperpolarized nuclei.
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Affiliation(s)
- William Beatrez
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Arjun Pillai
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Otto Janes
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Dieter Suter
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Ashok Ajoy
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Chemical Sciences Division, Berkeley, California 94720, USA
- CIFAR Azrieli Global Scholars Program, 661 University Ave, Toronto, ON M5G 1M1, Canada
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40
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Xie F, Mao H, Lin C, Feng Y, Stoddart JF, Young RM, Wasielewski MR. Quantum Sensing of Electric Fields Using Spin-Correlated Radical Ion Pairs. J Am Chem Soc 2023. [PMID: 37364237 DOI: 10.1021/jacs.3c04212] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Quantum sensing affords the possibility of using quantum entanglement to probe electromagnetic fields with exquisite sensitivity. In this work, we show that a photogenerated spin-correlated radical ion pair (SCRP) can be used to sense an electric field change created at one radical ion of the pair using molecular recognition. The SCRP is generated within a covalent donor-chromophore-acceptor system PXX-PMI-NDI, 1, where PXX = peri-xanthenoxanthene, PMI = 1,6-bis(p-t-butylphenoxy)perylene-3,4-dicarboximide, and NDI = naphthalene-1,8:4,5-bis(dicarboximide). The electron-rich PXX donor in 1 acts as a guest molecule that can be encapsulated selectively by a tetracationic cyclophane ExBox4+ host to give a supramolecular complex 1 ⊂ ExBox4+. Selective photoexcitation of the PMI chromophore results in ultrafast generation of the PXX•+-PMI-NDI•- SCRP. When PXX is encapsulated by ExBox4+, the cyclophane generates an electric field that repels the positive charge on PXX•+ within PXX•+-PMI-NDI•-, reducing the SCRP distance, i.e., the distance between the centers-of-charge on the donor and acceptor. Pulse-EPR measurements are used to measure the coherent oscillations created primarily by the electron-electron dipolar coupling in the SCRP, which yields the distance between the two charges (spins) of PXX•+-PMI-NDI•-. The experimental results show that the distance between PXX•+ and NDI•- decreases when ExBox4+ encapsulates PXX•+, which demonstrates that the SCRP can function as a quantum sensor to detect electric field changes in the vicinity of the radical ions.
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Affiliation(s)
- Fangbai Xie
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Haochuan Mao
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Chenjian Lin
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Yuanning Feng
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - J Fraser Stoddart
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311215, China
| | - Ryan M Young
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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41
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Taran G, Moreno-Pineda E, Schulze M, Bonet E, Ruben M, Wernsdorfer W. Direct determination of high-order transverse ligand field parameters via µSQUID-EPR in a Et 4N[ 160GdPc 2] SMM. Nat Commun 2023; 14:3361. [PMID: 37291099 DOI: 10.1038/s41467-023-39003-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 05/25/2023] [Indexed: 06/10/2023] Open
Abstract
The development of quantum technologies requires a thorough understanding of systems possessing quantum effects that can ultimately be manipulated. In the field of molecular magnetism, one of the main challenges is to measure high-order ligand field parameters, which play an essential role in the relaxation properties of SMMs. The development of highly advanced theoretical calculations has allowed the ab-initio determination of such parameters; however, currently, there is a lack of quantitative assessment of how good the ab-initio parameters are. In our quest for technologies that can allow the extraction of such elusive parameters, we develop an experimental technique that combines the EPR spectroscopy and µSQUID magnetometry. We demonstrate the power of the technique by performing EPR-µSQUID measurement of a magnetically diluted single crystal of Et4N[GdPc2], by sweeping the magnetic field and applying a range of multifrequency microwave pulses. As a result, we were able to directly determine the high-order ligand field parameters of the system, enabling us to test theoretical predictions made by state-of-the-art ab-initio methods.
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Affiliation(s)
- Gheorghe Taran
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76131, Karlsruhe, Germany
| | - Eufemio Moreno-Pineda
- Depto. de Química-Física, Facultad de Ciencias Naturales, Exactas y Tecnología, Universidad de Panamá, Panamá, Panamá.
- Grupo de Investigación de Materiales, Facultad de Ciencias Naturales, Exactas y Tecnología, Universidad de Panamá, Panamá, Panamá.
| | - Michael Schulze
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76131, Karlsruhe, Germany
| | - Edgar Bonet
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, Grenoble, 38000, France
| | - Mario Ruben
- Centre Européen de Sciences Quantiques (CESQ) within the Institut de Science et d'Ingénierie Supramoléculaires (ISIS), 8 allée Gaspard Monge, BP 70028, 67083, Strasbourg Cedex, France.
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Plats 1, D-76344, Eggenstein-Leopoldshafen, Germany.
- Institute for Quantum Materials and Technology (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344, Eggenstein-Leopoldshafen, Germany.
| | - Wolfgang Wernsdorfer
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76131, Karlsruhe, Germany.
- Institute for Quantum Materials and Technology (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344, Eggenstein-Leopoldshafen, Germany.
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42
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Yabuki R, Nishimura K, Hamachi T, Matsumoto N, Yanai N. Generation and Transfer of Triplet Electron Spin Polarization at the Solid-Liquid Interface. J Phys Chem Lett 2023; 14:4754-4759. [PMID: 37184433 DOI: 10.1021/acs.jpclett.3c00627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The photoexcited triplet state of dyes can generate highly polarized electron spins for sensing and dynamic nuclear polarization. However, while triplets exhibit long spin-lattice relaxation times (T1) on the microsecond scale in solids, the polarization quickly relaxes on the nanosecond scale in solution due to the rotational motion of chromophores. Here, we report that the immobilization of dye molecules on a solid surface allows molecular contact with a liquid while maintaining high polarization and long T1 as in a solid. By adsorbing anionic porphyrins on cationic mesoporous silica gel, porphyrin triplets exhibit high polarization and long T1 at the solid-liquid interface of silica and toluene. Furthermore, porphyrin triplets on the solid surface can exchange spin polarization with TEMPO radicals in solution. This simple and versatile method using the solid-liquid interface will open the door for utilizing the photoinduced triplet spin polarization in solution, which has been mainly limited to the solid-state.
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Affiliation(s)
- Reiya Yabuki
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Koki Nishimura
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tomoyuki Hamachi
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Naoto Matsumoto
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Nobuhiro Yanai
- Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
- FOREST, JST, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
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43
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Yin X, Deng L, Ruan L, Wu Y, Luo F, Qin G, Han X, Zhang X. Recent Progress for Single-Molecule Magnets Based on Rare Earth Elements. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093568. [PMID: 37176451 PMCID: PMC10180339 DOI: 10.3390/ma16093568] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 04/29/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
Single-molecule magnets (SMMs) have attracted much attention due to their potential applications in molecular spintronic devices. Rare earth SMMs are considered to be the most promising for application owing to their large magnetic moment and strong magnetic anisotropy. In this review, the recent progress in rare earth SMMs represented by mononuclear and dinuclear complexes is highlighted, especially for the modulation of magnetic anisotropy, effective energy barrier (Ueff) and blocking temperature (TB). The terbium- and dysprosium-based SMMs have a Ueff of 1541 cm-1 and an increased TB of 80 K. They break the boiling point temperature of liquid nitrogen. The development of the preparation technology of rare earth element SMMs is also summarized in an overview. This review has important implications and insights for the design and research of Ln-SMMs.
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Affiliation(s)
- Xiang Yin
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Li Deng
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Liuxia Ruan
- Research Center for Humanoid Sensing, Zhejiang Laboratory, Hangzhou 311100, China
| | - Yanzhao Wu
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Feifei Luo
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Gaowu Qin
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Xiaoli Han
- Taian Weiye Electromechanical Technology Co., Ltd., Taian 271000, China
| | - Xianmin Zhang
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
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44
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Tait CE, Krzyaniak MD, Stoll S. Computational tools for the simulation and analysis of spin-polarized EPR spectra. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 349:107410. [PMID: 36870248 DOI: 10.1016/j.jmr.2023.107410] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/10/2023] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
The EPR spectra of paramagnetic species induced by photoexcitation typically exhibit enhanced absorptive and emissive features resulting from sublevel populations that differ from thermal equilibrium. The populations and the resulting spin polarization of the spectra are dictated by the selectivity of the photophysical process generating the observed state. Simulation of the spin-polarized EPR spectra is crucial in the characterization of both the dynamics of formation of the photoexcited state as well as its electronic and structural properties. EasySpin, the simulation toolbox for EPR spectroscopy, now includes extended support for the simulation of the EPR spectra of spin-polarized states of arbitrary spin multiplicity and formed by a variety of different mechanisms, including photoexcited triplet states populated by intersystem crossing, charge recombination or spin polarization transfer, spin-correlated radical pairs created by photoinduced electron transfer, triplet pairs formed by singlet fission and multiplet states arising from photoexcitation in systems containing chromophores and stable radicals. In this paper, we highlight EasySpin's capabilities for the simulation of spin-polarized EPR spectra on the basis of illustrative examples from the literature in a variety of fields ranging across chemistry, biology, material science and quantum information science.
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Affiliation(s)
- Claudia E Tait
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom.
| | - Matthew D Krzyaniak
- Department of Chemistry, Center for Molecular Quantum Transduction and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston 60208, IL, United States
| | - Stefan Stoll
- Department of Chemistry, University of Washington, Seattle, 98195, WA, United States
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45
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Roseiro P, Yalouz S, Brook DJR, Ben Amor N, Robert V. Modifications of Tanabe-Sugano d6 Diagram Induced by Radical Ligand Field: Ab Initio Inspection of a Fe(II)-Verdazyl Molecular Complex. Inorg Chem 2023; 62:5737-5743. [PMID: 36971364 DOI: 10.1021/acs.inorgchem.3c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Quantum entanglement between the spin states of a metal center and radical ligands is suggested in an iron(II) [Fe(dipyvd)2]2+ compound (dipyvd = 1-isopropyl-3,5-dipyridil-6-oxoverdazyl). Wave function ab initio (Difference Dedicated Configuration Interaction, DDCI) inspections were carried out to stress the versatility of local spin states. We named this phenomenon excited state spinmerism, in reference to our previous work (see Roseiro et al., ChemPhysChem 2022, e202200478) where we introduced the concept of spinmerism as an extension of mesomerism to spin degrees of freedom. The construction of localized molecular orbitals allows for a reading of the wave functions and projections onto the local spin states. The low-energy spectrum is well-depicted by a Heisenberg picture. A 60 cm-1 ferromagnetic interaction is calculated between the radical ligands with the Stotal = 0 and 1 states largely dominated by a local low-spin SFe = 0. In contrast, the higher-lying Stotal = 2 states are superpositions of the local SFe = 1 (17%, 62%) and SFe = 2 (72%, 21%) spin states. Such mixing extends the traditional picture of a high-field d6 Tanabe-Sugano diagram. Even in the absence of spin-orbit coupling, the avoided crossing between different local spin states is triggered by the field generated by radical ligands. This puzzling scenario emerges from versatile local spin states in compounds which extend the traditional views in molecular magnetism.
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46
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Mao H, Pažėra GJ, Young RM, Krzyaniak MD, Wasielewski MR. Quantum Gate Operations on a Spectrally Addressable Photogenerated Molecular Electron Spin-Qubit Pair. J Am Chem Soc 2023; 145:6585-6593. [PMID: 36913602 DOI: 10.1021/jacs.3c01243] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Abstract
Sub-nanosecond photodriven electron transfer from a molecular donor to an acceptor can be used to generate a radical pair (RP) having two entangled electron spins in a well-defined pure initial singlet quantum state to serve as a spin-qubit pair (SQP). Achieving good spin-qubit addressability is challenging because many organic radical ions have large hyperfine couplings (HFCs) in addition to significant g-anisotropy, which results in significant spectral overlap. Moreover, using radicals with g-factors that deviate significantly from that of the free electron results in difficulty generating microwave pulses with sufficiently large bandwidths to manipulate the two spins either simultaneously or selectively as is necessary to implement the controlled-NOT (CNOT) quantum gate essential for quantum algorithms. Here, we address these issues by using a covalently linked donor-acceptor(1)-acceptor(2) (D-A1-A2) molecule with significantly reduced HFCs that uses fully deuterated peri-xanthenoxanthene (PXX) as D, naphthalenemonoimide (NMI) as A1, and a C60 derivative as A2. Selective photoexcitation of PXX within PXX-d9-NMI-C60 results in sub-nanosecond, two-step electron transfer to generate the long-lived PXX•+-d9-NMI-C60•- SQP. Alignment of PXX•+-d9-NMI-C60•- in the nematic liquid crystal 4-cyano-4'-(n-pentyl)biphenyl (5CB) at cryogenic temperatures results in well-resolved, narrow resonances for each electron spin. We demonstrate both single-qubit gate and two-qubit CNOT gate operations using both selective and nonselective Gaussian-shaped microwave pulses and broadband spectral detection of the spin states following the gate operations.
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Affiliation(s)
- Haochuan Mao
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Gediminas J Pažėra
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
| | - Ryan M Young
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Matthew D Krzyaniak
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
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47
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Dill RD, Smyser KE, Rugg BK, Damrauer NH, Eaves JD. Entangled spin-polarized excitons from singlet fission in a rigid dimer. Nat Commun 2023; 14:1180. [PMID: 36859382 PMCID: PMC9977721 DOI: 10.1038/s41467-023-36529-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 01/31/2023] [Indexed: 03/03/2023] Open
Abstract
Singlet fission, a process that splits a singlet exciton into a biexciton, has promise in quantum information. We report time-resolved electron paramagnetic resonance measurements on a conformationally well-defined acene dimer molecule, TIPS-BP1', designed to exhibit strongly state-selective relaxation to specific magnetic spin sublevels. The resulting optically pumped spin polarization is a nearly pure initial state from the ensemble. The long-lived spin coherences modulate the signal intrinsically, allowing a measurement scheme that substantially removes noise and uncertainty in the magnetic resonance spectra. A nonadiabatic transition theory with a minimal number of spectroscopic parameters allows the quantitative assignment and interpretation of the spectra. In this work, we show that the rigid dimer TIPS-BP1' supports persistent spin coherences at temperatures far higher than those used in conventional superconducting quantum hardware.
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Affiliation(s)
- Ryan D. Dill
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Kori E. Smyser
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Brandon K. Rugg
- grid.419357.d0000 0001 2199 3636National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Niels H. Damrauer
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA ,grid.266190.a0000000096214564Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Joel D. Eaves
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA ,grid.266190.a0000000096214564Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309 USA
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48
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Tesi L, Stemmler F, Winkler M, Liu SSY, Das S, Sun X, Zharnikov M, Ludwigs S, van Slageren J. Modular Approach to Creating Functionalized Surface Arrays of Molecular Qubits. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208998. [PMID: 36609776 DOI: 10.1002/adma.202208998] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/30/2022] [Indexed: 06/17/2023]
Abstract
The quest for developing quantum technologies is driven by the promise of exponentially faster computations, ultrahigh performance sensing, and achieving thorough understanding of many-particle quantum systems. Molecular spins are excellent qubit candidates because they feature long coherence times, are widely tunable through chemical synthesis, and can be interfaced with other quantum platforms such as superconducting qubits. A present challenge for molecular spin qubits is their integration in quantum devices, which requires arranging them in thin films or monolayers on surfaces. However, clear proof of the survival of quantum properties of molecular qubits on surfaces has not been reported so far. Furthermore, little is known about the change in spin dynamics of molecular qubits going from the bulk to monolayers. Here, a versatile bottom-up method is reported to arrange molecular qubits as functional groups of self-assembled monolayers (SAMs) on surfaces, combining molecular self-organization and click chemistry. Coherence times of up to 13 µs demonstrate that qubit properties are maintained or even enhanced in the monolayer.
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Affiliation(s)
- Lorenzo Tesi
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Friedrich Stemmler
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Mario Winkler
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Sherri S Y Liu
- IPOC-Functional Polymers, Institute of Polymer Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Saunak Das
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Xiuming Sun
- IPOC-Functional Polymers, Institute of Polymer Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Michael Zharnikov
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Sabine Ludwigs
- IPOC-Functional Polymers, Institute of Polymer Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Joris van Slageren
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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49
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Campanella AJ, Üngör Ö, Zadrozny JM. Quantum Mimicry With Inorganic Chemistry. COMMENT INORG CHEM 2023; 44:11-53. [PMID: 38515928 PMCID: PMC10954259 DOI: 10.1080/02603594.2023.2173588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Quantum objects, such as atoms, spins, and subatomic particles, have important properties due to their unique physical properties that could be useful for many different applications, ranging from quantum information processing to magnetic resonance imaging. Molecular species also exhibit quantum properties, and these properties are fundamentally tunable by synthetic design, unlike ions isolated in a quadrupolar trap, for example. In this comment, we collect multiple, distinct, scientific efforts into an emergent field that is devoted to designing molecules that mimic the quantum properties of objects like trapped atoms or defects in solids. Mimicry is endemic in inorganic chemistry and featured heavily in the research interests of groups across the world. We describe a new field of using inorganic chemistry to design molecules that mimic the quantum properties (e.g. the lifetime of spin superpositions, or the resonant frequencies thereof) of other quantum objects, "quantum mimicry." In this comment, we describe the philosophical design strategies and recent exciting results from application of these strategies.
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Affiliation(s)
- Anthony J. Campanella
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
| | - Ökten Üngör
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
| | - Joseph M. Zadrozny
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
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50
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Dorn M, Hunger D, Förster C, Naumann R, van Slageren J, Heinze K. Towards Luminescent Vanadium(II) Complexes with Slow Magnetic Relaxation and Quantum Coherence. Chemistry 2023; 29:e202202898. [PMID: 36345821 PMCID: PMC10107508 DOI: 10.1002/chem.202202898] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/11/2022]
Abstract
Molecular entities with doublet or triplet ground states find increasing interest as potential molecular quantum bits (qubits). Complexes with higher multiplicity might even function as qudits and serve to encode further quantum bits. Vanadium(II) ions in octahedral ligand fields with quartet ground states and small zero-field splittings qualify as qubits with optical read out thanks to potentially luminescent spin-flip states. We identified two V2+ complexes [V(ddpd)2 ]2+ with the strong field ligand N,N'-dimethyl-N,N'-dipyridine-2-yl-pyridine-2,6-diamine (ddpd) in two isomeric forms (cis-fac and mer) as suitable candidates. The energy gaps between the two lowest Kramers doublets amount to 0.2 and 0.5 cm-1 allowing pulsed EPR experiments at conventional Q-band frequencies (35 GHz). Both isomers possess spin-lattice relaxation times T1 of around 300 μs and a phase memory time TM of around 1 μs at 5 K. Furthermore, the mer isomer displays slow magnetic relaxation in an applied field of 400 mT. While the vanadium(III) complexes [V(ddpd)2 ]3+ are emissive in the near-IR-II region, the [V(ddpd)2 ]2+ complexes are non-luminescent due to metal-to-ligand charge transfer admixture to the spin-flip states.
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Affiliation(s)
- Matthias Dorn
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128, Mainz, Germany
| | - David Hunger
- Institute of Physical Chemistry and Center for, Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Joris van Slageren
- Institute of Physical Chemistry and Center for, Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128, Mainz, Germany
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