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Gabarró-Riera G, Sañudo EC. Challenges for exploiting nanomagnet properties on surfaces. Commun Chem 2024; 7:99. [PMID: 38693350 PMCID: PMC11063158 DOI: 10.1038/s42004-024-01183-6] [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] [Received: 11/28/2023] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
Molecular complexes with single-molecule magnet (SMM) or qubit properties, commonly called molecular nanomagnets, are great candidates for information storage or quantum information processing technologies. However, the implementation of molecular nanomagnets in devices for the above-mentioned applications requires controlled surface deposition and addressing the nanomagnets' properties on the surface. This Perspectives paper gives a brief overview of molecular properties on a surface relevant for magnetic molecules and how they are affected when the molecules interact with a surface; then, we focus on systems of increasing complexity, where the relevant SMMs and qubit properties have been observed for the molecules deposited on surfaces; finally, future perspectives, including possible ways of overcoming the problems encountered so far are discussed.
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Affiliation(s)
- Guillem Gabarró-Riera
- Institut de Nanociència i Nanotecnologia, Universitat de Barcelona IN2UB, C/Martí i Franqués 1-11, 08028, Barcelona, Spain
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, C/Martí i Franqués 1-11, 08028, Barcelona, Spain
| | - E Carolina Sañudo
- Institut de Nanociència i Nanotecnologia, Universitat de Barcelona IN2UB, C/Martí i Franqués 1-11, 08028, Barcelona, Spain.
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, C/Martí i Franqués 1-11, 08028, Barcelona, Spain.
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2
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Monakhov KY. Oxovanadium electronics for in-memory, neuromorphic, and quantum computing applications. MATERIALS HORIZONS 2024; 11:1838-1842. [PMID: 38334459 DOI: 10.1039/d3mh01926h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Vanadium is a critical raw material. In the nearby future, it may, however, become one of the key elements of computer devices based on two-dimensional arrays of spin qubits for quantum information processing or charge- and resistance-based data memory cells for non-volatile in-memory and neuromorphic computing. The research and development (R&D) of vanadium-containing electronic materials and methods for their responsible fabrication underpins the transition to innovative hybrid semiconductors for energy- and resource-efficient memory and information processing technologies. The combination of standard and emerging solid-state semiconductors with stimuli-responsive oxo complexes of vanadium(IV,V) is envisioned to result in electronics with a new room-temperature device nanophysics, and the ability to modulate and control it at the sub-nanometer level. The development of exponential (Boolean) logics based on the oxovanadium-comprising circuitry and crossbar arrays of individual memristive cells for in-memory computing, the implementation of basic synaptic functions via dynamic electrical pulses for neuromorphic computing, and the readout and control of spin networks and interfaces for quantum computing are strategically important future areas of molecular chemistry and applied physics of vanadium.
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Affiliation(s)
- Kirill Yu Monakhov
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig 04318, Germany.
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3
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Baumann S, McMurtrie G, Hänze M, Betz N, Arnhold L, Malavolti L, Loth S. An Atomic-Scale Vector Network Analyzer. SMALL METHODS 2024:e2301526. [PMID: 38381093 DOI: 10.1002/smtd.202301526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/16/2024] [Indexed: 02/22/2024]
Abstract
Electronic devices have been ever-shrinking toward atomic dimensions and have reached operation frequencies in the GHz range, thereby outperforming most conventional test equipment, such as vector network analyzers (VNA). Here the capabilities of a VNA on the atomic scale in a scanning tunneling microscope are implemented. Nonlinearities present in the voltage-current characteristic of atoms and nanostructures for phase-resolved microwave spectroscopy with unprecedented spatial resolution at GHz frequencies are exploited. The amplitude and phase response up to 9.3 GHz is determined, which permits accurate de-embedding of the transmission line and application of distortion-corrected waveforms in the tunnel junction itself. This enables quantitative characterization of the complex-valued admittance of individual magnetic iron atoms which show a lowpass response with a magnetic-field-tunable cutoff frequency.
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Affiliation(s)
- Susanne Baumann
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
| | - Gregory McMurtrie
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
| | - Max Hänze
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - Nicolaj Betz
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
| | - Lukas Arnhold
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
| | - Luigi Malavolti
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
| | - Sebastian Loth
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569, Stuttgart, Germany
- Max Planck Institute for Solid State Research, 70569, Stuttgart, Germany
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4
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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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5
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Karan S, Huang H, Ivanovic A, Padurariu C, Kubala B, Kern K, Ankerhold J, Ast CR. Tracking a spin-polarized superconducting bound state across a quantum phase transition. Nat Commun 2024; 15:459. [PMID: 38212303 PMCID: PMC10784290 DOI: 10.1038/s41467-024-44708-2] [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] [Received: 04/17/2023] [Accepted: 01/02/2024] [Indexed: 01/13/2024] Open
Abstract
The magnetic exchange coupling between magnetic impurities and a superconductor induce so-called Yu-Shiba-Rusinov (YSR) states which undergo a quantum phase transition (QPT) upon increasing the exchange interaction beyond a critical value. While the evolution through the QPT is readily observable, in particular if the YSR state features an electron-hole asymmetry, the concomitant change in the ground state is more difficult to identify. We use ultralow temperature scanning tunneling microscopy to demonstrate how the change in the YSR ground state across the QPT can be directly observed for a spin-1/2 impurity in a magnetic field. The excitation spectrum changes from featuring two peaks in the doublet (free spin) state to four peaks in the singlet (screened spin) ground state. We also identify a transition regime, where the YSR excitation energy is smaller than the Zeeman energy. We thus demonstrate a straightforward way for unambiguously identifying the ground state of a spin-1/2 YSR state.
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Affiliation(s)
- Sujoy Karan
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany.
| | - Haonan Huang
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Alexander Ivanovic
- Institute for Complex Quantum Systems and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
| | - Ciprian Padurariu
- Institute for Complex Quantum Systems and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
| | - Björn Kubala
- Institute for Complex Quantum Systems and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
- Institute for Quantum Technologies, German Aerospace Center (DLR), Wilhelm-Runge-Straße 10, 89081, Ulm, Germany
| | - Klaus Kern
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany
- Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - Joachim Ankerhold
- Institute for Complex Quantum Systems and IQST, Universität Ulm, Albert-Einstein-Allee 11, 89069, Ulm, Germany
| | - Christian R Ast
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany.
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6
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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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Liu Y, Li C, Xue FH, Su W, Wang Y, Huang H, Yang H, Chen J, Guan D, Li Y, Zheng H, Liu C, Qin M, Wang X, Wang R, Li DY, Liu PN, Wang S, Jia J. Quantum Phase Transition in Magnetic Nanographenes on a Lead Superconductor. NANO LETTERS 2023; 23:9704-9710. [PMID: 37870505 DOI: 10.1021/acs.nanolett.3c02208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
Quantum spins, also known as spin operators that preserve SU(2) symmetry, lack a specific orientation in space and are hypothesized to display unique interactions with superconductivity. However, spin-orbit coupling and crystal field typically cause a significant magnetic anisotropy in d/f shell spins on surfaces. Here, we fabricate atomically precise S = 1/2 magnetic nanographenes on Pb(111) through engineering sublattice imbalance in the graphene honeycomb lattice. Through tuning the magnetic exchange strength between the unpaired spin and Cooper pairs, a quantum phase transition from the singlet to the doublet state has been observed, consistent with the quantum spin models. From our calculations, the particle-hole asymmetry is induced by the Coulomb scattering potential and gives a transition point about kBTk ≈ 1.6Δ. Our work demonstrates that delocalized π electron magnetism hosts highly tunable magnetic bound states, which can be further developed to study the Majorana bound states and other rich quantum phases of low-dimensional quantum spins on superconductors.
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Affiliation(s)
- Yu Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Can Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Fu-Hua Xue
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science Technology, 130 Meilong Road, Shanghai 200237, China
| | - Wei Su
- Beijing Computational Science Research Center, Beijing 100084, China
- College of Physics and Electronic Engineering, Center for Computational Sciences, Sichuan Normal University, Chengdu 610068, China
| | - Ying Wang
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science Technology, 130 Meilong Road, Shanghai 200237, China
| | - Haili Huang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Hao Yang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Jiayi Chen
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Dandan Guan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Yaoyi Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Hao Zheng
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Canhua Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Mingpu Qin
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiaoqun Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center for Advanced Microstructures, Nanjing 210093, China
| | - Deng-Yuan Li
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science Technology, 130 Meilong Road, Shanghai 200237, China
| | - Pei-Nian Liu
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science Technology, 130 Meilong Road, Shanghai 200237, China
| | - Shiyong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
| | - Jinfeng Jia
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), TD Lee Institute, Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
- Hefei National Laboratory, Hefei 230088, China
- Shanghai Research Center for Quantum Sciences, 99 Xiupu Road, Shanghai 201315, China
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8
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Tejedor I, Urtizberea A, Natividad E, Martínez JI, Gascón I, Roubeau O. Dilute Gd hydroxycarbonate particles for localized spin qubit integration. MATERIALS HORIZONS 2023; 10:5214-5222. [PMID: 37725390 DOI: 10.1039/d3mh01201h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Molecular spins are considered as the quantum hardware to build hybrid quantum processors in which coupling to superconducting devices would provide the means to implement the necessary coherent manipulations. As an alternative to large magnetically-dilute crystals or concentrated nano-scale deposits of paramagnetic molecules that have been studied so far, the use of pre-formed sub-micronic spherical particles of a doped Gd@Y hydroxycarbonate is evaluated here. Particles with an adjustable number of spin carriers are prepared through the control of both particle size and doping. Bulk magnetic properties and continuous wave and time-domain-EPR spectroscopy show that the Gd spins in these particles are potential qubits with robust quantum coherence. Monolayers of densely-packed particles are then formed interfacially and transferred successfully to the surface of Nb superconducting resonators. Alternatively, these particles are disposed at controlled localizations as isolated groups of a few particles through Dip-Pen Nanolithography using colloidal organic dispersions as ink. Altogether, this study offers new material and methodologies relevant to the development of viable hybrid quantum processors.
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Affiliation(s)
- Inés Tejedor
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009 Zaragoza, Spain
| | - Ainhoa Urtizberea
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Campus Río Ebro, María de Luna 3, 50018 Zaragoza, Spain.
| | - Eva Natividad
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Campus Río Ebro, María de Luna 3, 50018 Zaragoza, Spain.
| | - Jesús I Martínez
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009 Zaragoza, Spain
| | - Ignacio Gascón
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009 Zaragoza, Spain
| | - Olivier Roubeau
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009 Zaragoza, Spain
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9
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Drost R, Kezilebieke S, Lado JL, Liljeroth P. Real-Space Imaging of Triplon Excitations in Engineered Quantum Magnets. PHYSICAL REVIEW LETTERS 2023; 131:086701. [PMID: 37683177 DOI: 10.1103/physrevlett.131.086701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/15/2023] [Accepted: 07/24/2023] [Indexed: 09/10/2023]
Abstract
Quantum magnets provide a powerful platform to explore complex quantum many-body phenomena. One example is triplon excitations, exotic many-body modes emerging from propagating singlet-triplet transitions. We engineer a minimal quantum magnet from organic molecules and demonstrate the emergence of dispersive triplon modes in one- and two-dimensional assemblies probed with scanning tunneling microscopy and spectroscopy. Our results provide the first demonstration of dispersive triplon excitations from a real-space measurement.
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Affiliation(s)
- Robert Drost
- Aalto University, Department of Applied Physics, 00076 Aalto, Finland
| | - Shawulienu Kezilebieke
- Department of Physics, Department of Chemistry and Nanoscience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Jose L Lado
- Aalto University, Department of Applied Physics, 00076 Aalto, Finland
| | - Peter Liljeroth
- Aalto University, Department of Applied Physics, 00076 Aalto, Finland
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10
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Noh K, Colazzo L, Urdaniz C, Lee J, Krylov D, Devi P, Doll A, Heinrich AJ, Wolf C, Donati F, Bae Y. Template-directed 2D nanopatterning of S = 1/2 molecular spins. NANOSCALE HORIZONS 2023; 8:624-631. [PMID: 36752198 DOI: 10.1039/d2nh00375a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Molecular spins are emerging platforms for quantum information processing. By chemically tuning their molecular structure, it is possible to prepare a robust environment for electron spins and drive the assembly of a large number of qubits in atomically precise spin-architectures. The main challenges in the integration of molecular qubits into solid-state devices are (i) minimizing the interaction with the supporting substrate to suppress quantum decoherence and (ii) controlling the spatial distribution of the spins at the nanometer scale to tailor the coupling among qubits. Herein, we provide a nanofabrication method for the realization of a 2D patterned array of individually addressable Vanadyl Phthalocyanine (VOPc) spin qubits. The molecular nanoarchitecture is crafted on top of a diamagnetic monolayer of Titanyl Phthalocyanine (TiOPc) that electronically decouples the electronic spin of VOPc from the underlying Ag(100) substrate. The isostructural TiOPc interlayer also serves as a template to regulate the spacing between VOPc spin qubits on a scale of a few nanometers, as demonstrated using scanning tunneling microscopy, X-ray circular dichroism, and density functional theory. The long-range molecular ordering is due to a combination of charge transfer from the metallic substrate and strain in the TiOPc interlayer, which is attained without altering the pristine VOPc spin characteristics. Our results pave a viable route towards the future integration of molecular spin qubits into solid-state devices.
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Affiliation(s)
- Kyungju Noh
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Luciano Colazzo
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Corina Urdaniz
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Jaehyun Lee
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Denis Krylov
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Parul Devi
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Andrin Doll
- Swiss Light Source (SLS), Paul Scherrer Institut (PSI), 5232 Villigen, Switzerland
| | - Andreas J Heinrich
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Christoph Wolf
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Fabio Donati
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
| | - Yujeong Bae
- Center for Quantum Nanoscience (QNS), Institute of Basic Science (IBS), 03760 Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, 03760 Seoul, Republic of Korea
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11
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Trivini S, Ortuzar J, Vaxevani K, Li J, Bergeret FS, Cazalilla MA, Pascual JI. Cooper Pair Excitation Mediated by a Molecular Quantum Spin on a Superconducting Proximitized Gold Film. PHYSICAL REVIEW LETTERS 2023; 130:136004. [PMID: 37067302 DOI: 10.1103/physrevlett.130.136004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 02/17/2023] [Indexed: 06/19/2023]
Abstract
Breaking a correlated pair in a superconductor requires an even number of fermions providing at least twice the pairing energy Δ. Here, we show that a single tunneling electron can also excite a pair breaking excitation in a proximitized gold film in the presence of magnetic impurities. Combining scanning tunneling spectroscopy with theoretical modeling, we map the excitation spectrum of an Fe-porphyrin molecule on the Au/V(100) proximitized surface into a manifold of entangled Yu-Shiba-Rusinov and spin excitations. Pair excitations emerge in the tunneling spectra as peaks outside the spectral gap only in the strong coupling regime, where the presence of a bound quasiparticle in the ground state ensures the even fermion parity of the excitation. Our results unravel the quantum nature of magnetic impurities on superconductors and demonstrate that pair excitations unequivocally reveal the parity of the ground state.
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Affiliation(s)
| | - Jon Ortuzar
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
| | | | - Jingchen Li
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- School of Physics, Sun Yat-sen University, Guangzhou 510275, China
| | - F Sebastian Bergeret
- Centro de Física de Materiales (CFM-MPC) Centro Mixto CSIC-UPV/EHU, E-20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastian, Spain
| | - Miguel A Cazalilla
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastian, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Jose Ignacio Pascual
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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12
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Schulte S, Néel N, Rózsa L, Palotás K, Kröger J. Changing the Interaction of a Single-Molecule Magnetic Moment with a Superconductor. NANO LETTERS 2023; 23:1622-1628. [PMID: 36603183 DOI: 10.1021/acs.nanolett.2c03952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The exchange interaction of a brominated Co-porphyrin molecule with the Cooper pair condensate of Pb(111) is modified by reducing the Co-surface separation. The stepwise dehalogenation and dephenylation change the Co adsorption height by a few picometers. Only the residual Co-porphine core exhibits a Yu-Shiba-Rusinov bound state with low binding energy in the Bardeen-Cooper-Schrieffer energy gap. Accompanying density functional calculations reveal that the Co dz2 orbital carries the molecular magnetic moment and is responsible for the intragap state. The calculated spatial evolution of the Yu-Shiba-Rusinov wave function is compatible with the experimentally observed oscillatory attenuation of the electron-hole asymmetry with increasing lateral distance from the magnetic porphine center.
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Affiliation(s)
- Stefan Schulte
- Institut für Physik, Technische Universität Ilmenau, D-98693Ilmenau, Germany
- Peter Grünberg Institut, Forschungszentrum Jülich, D-52425Jülich, Germany
- II. Physikalisches Institut, Universität zu Köln, D-50923Cologne, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693Ilmenau, Germany
| | - Levente Rózsa
- Fachbereich Physik, Universität Konstanz, D-78457Konstanz, Germany
| | - Krisztián Palotás
- Department of Theoretical Solid State Physics, Institute for Solid State Physics and Optics, Wigner Research Center for Physics, H-1121Budapest, Hungary
- ELKH-SZTE Reaction Kinetics and Surface Chemistry Research Group, University of Szeged, H-6720Szeged, Hungary
- Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, H-1111Budapest, Hungary
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693Ilmenau, Germany
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13
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Magnetic molecules on surfaces: SMMs and beyond. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Meng X, Möller J, Mansouri M, Sánchez-Portal D, Garcia-Lekue A, Weismann A, Li C, Herges R, Berndt R. Controlling the Spin States of FeTBrPP on Au(111). ACS NANO 2022; 17:1268-1274. [PMID: 36440841 DOI: 10.1021/acsnano.2c09310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Spin-flip excitations of iron porphyrin molecules on Au(111) are investigated with a low-temperature scanning tunneling microscope. The molecules adopt two distinct adsorption configurations on the surface that exhibit different magnetic anisotropy energies. Density functional theory calculations show that the different structures and excitation energies reflect unlike occupations of the Fe 3d levels. We demonstrate that the magnetic anisotropy energy can be controlled by changing the adsorption site, the orientation, or the tip-molecule distance.
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Affiliation(s)
- Xiangzhi Meng
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Jenny Möller
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Masoud Mansouri
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Daniel Sánchez-Portal
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Aran Garcia-Lekue
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013Bilbao, Spain
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Chao Li
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
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15
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Briganti M, Serrano G, Poggini L, Sorrentino AL, Cortigiani B, de Camargo LC, Soares JF, Motta A, Caneschi A, Mannini M, Totti F, Sessoli R. Mixed-Sandwich Titanium(III) Qubits on Au(111): Electron Delocalization Ruled by Molecular Packing. NANO LETTERS 2022; 22:8626-8632. [PMID: 36256878 PMCID: PMC9650780 DOI: 10.1021/acs.nanolett.2c03161] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/07/2022] [Indexed: 06/15/2023]
Abstract
Organometallic sandwich complexes are versatile molecular systems that have been recently employed for single-molecule manipulation and spin sensing experiments. Among related organometallic compounds, the mixed-sandwich S = 1/2 complex (η8-cyclooctatetraene)(η5-cyclopentadienyl)titanium, here [CpTi(cot)], has attracted interest as a spin qubit because of the long coherence time. Here the structural and chemical properties of [CpTi(cot)] on Au(111) are investigated at the monolayer level by experimental and computational methods. Scanning tunneling microscopy suggests that adsorption occurs in two molecular orientations, lying and standing, with a 3:1 ratio. XPS data evidence that a fraction of the molecules undergo partial electron transfer to gold, while our computational analysis suggests that only the standing molecules experience charge delocalization toward the surface. Such a phenomenon depends on intermolecular interactions that stabilize the molecular packing in the monolayer. This orientation-dependent molecule-surface hybridization opens exciting perspectives for selective control of the molecule-substrate spin delocalization in hybrid interfaces.
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Affiliation(s)
- Matteo Briganti
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Giulia Serrano
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Lorenzo Poggini
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Institute
for Chemistry of OrganoMetallic Compounds (ICCOM-CNR), Via Madonna del Piano, 50019 Sesto Fiorentino (FI) Italy
| | - Andrea Luigi Sorrentino
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Brunetto Cortigiani
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Luana Carol de Camargo
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Jaísa Fernandes Soares
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Alessandro Motta
- “La
Sapienza” and INSTM Research Unit, University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Andrea Caneschi
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Matteo Mannini
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Federico Totti
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Roberta Sessoli
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
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16
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Spin-orbital Yu-Shiba-Rusinov states in single Kondo molecular magnet. Nat Commun 2022; 13:6388. [PMID: 36302772 PMCID: PMC9613647 DOI: 10.1038/s41467-022-34187-8] [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: 12/09/2021] [Accepted: 10/13/2022] [Indexed: 11/18/2022] Open
Abstract
Studies of single-spin objects are essential for designing emergent quantum states. We investigate a molecular magnet Tb2Pc3 interacting with a superconducting Pb(111) substrate, which hosts unprecedented Yu-Shiba-Rusinov (YSR) subgap states, dubbed spin-orbital YSR states. Upon adsorption of the molecule on Pb, the degeneracy of its lowest unoccupied molecular orbitals (LUMO) is lifted, and the lower LUMO forms a radical spin via charge transfer. This leads to Kondo screening and subgap states. Intriguingly, the YSR states display two pairs of resonances with clearly distinct behavior. The energy of the inner pair exhibits prominent inter and intra molecular variation, and it strongly depends on the tip height. The outer pair, however, shifts only slightly. As is unveiled through theoretical calculations, the two pairs of YSR states originate from the ligand spin and charge-fluctuating higher LUMO, coexisting in a single molecule, but only weakly coupled presumably due to different spatial distribution. Our work paves the way for understanding complex many-body excitations and constructing molecule-based topological superconductivity. Yu-Shiba-Rusinov (YSR) states result from the exchange coupling between a localized magnetic moment and a superconductor. Traditionally, the YSR states have been studied for magnetic atoms. For molecular magnets with extended ligand spin, the entanglement of spin and ligand orbital gives rise to new forms of YSR excitations. Here, Xia et al uncovered spin-orbital YSR states in an unpaired ligand spin in the molecular magnet Tb2Pc3 on Pb.
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17
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Ayani CG, Calleja F, Ibarburu IM, Casado Aguilar P, Nazriq NKM, Yamada TK, Garnica M, Vázquez de Parga AL, Miranda R. Switchable molecular functionalization of an STM tip: from a Yu-Shiba-Rusinov Tip to a Kondo tip. NANOSCALE 2022; 14:15111-15118. [PMID: 36205255 DOI: 10.1039/d1nr08227b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this work we fabricate and characterize a functionalized superconducting (SC) Nb tip of a scanning tunnelling microscope (STM). The tip is functionalized with a Tetracyanoquinodimethane molecule (TCNQ) that accepts charge from the tip and develops a magnetic moment. As a consequence, in scanning tunnelling spectroscopy (STS), sharp, bias symmetric sub-gap states identified as Yu-Shiba-Rusinov (YSR) bound states appear against the featureless density of states of a metallic graphene on Ir(111) sample. Although the coupling regime of the magnetic impurity with the SC tip depends on the initial absorption configuration of the molecule, the interaction strength between the SC tip and the charged TCNQ molecule can be reversibly controlled by tuning the tip-sample distance. The controlled transition from one coupling regime to the other allows us to verify the relation between the energy scales of the two competing many-body effects for the functionalized tip. Quenching the SC state of the Nb tip with a magnetic field switches abruptly from a tip dominated by the YSR bound states to a Kondo tip.
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Affiliation(s)
- Cosme G Ayani
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
| | - Fabian Calleja
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
| | - Ivan M Ibarburu
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
| | - Pablo Casado Aguilar
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
| | - Nana K M Nazriq
- Department of Materials Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Toyo K Yamada
- Department of Materials Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
- Molecular Chirality Research center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Manuela Garnica
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
- Instituto 'Nicolás Cabrera', Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Amadeo L Vázquez de Parga
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
- Condensed Matter Physics Center (IFIMAC), Cantoblanco 28049, Madrid, Spain
- Instituto 'Nicolás Cabrera', Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rodolfo Miranda
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain
- IMDEA-Nanociencia, Calle Faraday 9, Cantoblanco 28049, Madrid, Spain.
- Condensed Matter Physics Center (IFIMAC), Cantoblanco 28049, Madrid, Spain
- Instituto 'Nicolás Cabrera', Universidad Autónoma de Madrid, 28049 Madrid, Spain
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18
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Magnetic molecules as local sensors of topological hysteresis of superconductors. Nat Commun 2022; 13:3838. [PMID: 35788608 PMCID: PMC9253336 DOI: 10.1038/s41467-022-31320-5] [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: 12/13/2021] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
Superconductors and magnetic materials, including molecules, are key ingredients for quantum computing and spintronics. However, only a little is known about how these materials interact in multilayer nanostructures like the hybrid architectures nowadays under development for such advanced applications. Here, we show that a single layer of magnetic molecules, Terbium(III) bis-phthalocyaninato (TbPc2) complexes, deposited under controlled UHV conditions on a superconducting Pb(111) surface is sensitive to the topology of the intermediate state of the superconductor, namely to the presence and evolution of superconducting and normal domains due to screening and penetration of an external magnetic field. The topological hysteresis of the superconducting substrate imprints a local evolution of the magnetisation of the TbPc2 molecules in the monolayer. Element and surface selective detection is achieved by recording the X-ray magnetic circular dichroism of the Tb atoms. This study reveals the impressive potential of magnetic molecules for sensing local magnetic field variations in molecular/superconductor hybrid devices, including spin resonators or spin injecting and spin filtering components for spintronics applications.
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19
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Xu Z, Romankov V, Doll A, Dreiser J. Orienting dilute thin films of non-planar spin-1/2 vanadyl-phthalocyanine complexes. MATERIALS ADVANCES 2022; 3:4938-4946. [PMID: 35812836 PMCID: PMC9207598 DOI: 10.1039/d2ma00157h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
The molecular orientation as well as the electronic and magnetic properties of vanadyl-phthalocyanine (VOPc) diluted into titanyl-phthalocyanine (TiOPc) thin films on Si(100) and polycrystalline aluminum substrates have been investigated by soft X-ray absorption spectroscopy (XAS), X-ray linear dichroism (XLD) and X-ray magnetic circular dichroism (XMCD). On the bare substrates the films grow with a standing-up geometry. By contrast, on template layers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA), they assume a lying-down orientation. Moreover, a theoretical model based on the normalized intensity of the nitrogen K-edge XLD is established in order to extract the molecular orientation angle quantitatively without the need for crystallinity and with the sub-monolayer sensitivity of soft-XAS. XMCD reveals that the vanadium magnetic properties are preserved in both non-diluted and diluted films. The results pave the way toward the use of VOPc as nanometer-sized spin quantum bits.
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Affiliation(s)
- Zhewen Xu
- Swiss Light Source, Paul Scherrer Institut Forschungsstrasse 111 CH-5232 Villigen PSI Switzerland
| | - Vladyslav Romankov
- Swiss Light Source, Paul Scherrer Institut Forschungsstrasse 111 CH-5232 Villigen PSI Switzerland
| | - Andrin Doll
- Swiss Light Source, Paul Scherrer Institut Forschungsstrasse 111 CH-5232 Villigen PSI Switzerland
| | - Jan Dreiser
- Swiss Light Source, Paul Scherrer Institut Forschungsstrasse 111 CH-5232 Villigen PSI Switzerland
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20
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Thupakula U, Perrin V, Palacio-Morales A, Cario L, Aprili M, Simon P, Massee F. Coherent and Incoherent Tunneling into Yu-Shiba-Rusinov States Revealed by Atomic Scale Shot-Noise Spectroscopy. PHYSICAL REVIEW LETTERS 2022; 128:247001. [PMID: 35776485 DOI: 10.1103/physrevlett.128.247001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/27/2021] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
The pair breaking potential of individual magnetic impurities in s-wave superconductors generates localized states inside the superconducting gap commonly referred to as Yu-Shiba-Rusinov (YSR) states whose isolated nature makes them promising building blocks for artificial structures that may host Majorana fermions. One of the challenges in this endeavor is to understand their intrinsic lifetime, ℏ/Λ, which is expected to be limited by the inelastic coupling with the continuum thus leading to decoherence. Here we use shot-noise scanning tunneling microscopy to reveal that electron tunneling into superconducting 2H-NbSe_{2} mediated by YSR states is not Poissonian, but ordered as a function of time, as evidenced by a reduction of the noise. Moreover, our data show the concomitant transfer of charges e and 2e, indicating that incoherent single particle and coherent Andreev processes operate simultaneously. From the quantitative agreement between experiment and theory we obtain Λ=1 μeV≪k_{B}T demonstrating that shot noise can probe energy scales and timescales inaccessible by conventional spectroscopy whose resolution is thermally limited.
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Affiliation(s)
- U Thupakula
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
| | - V Perrin
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
| | - A Palacio-Morales
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
| | - L Cario
- Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel, IMN, F-44000 Nantes, France
| | - M Aprili
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
| | - P Simon
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
| | - F Massee
- Laboratoire de Physique des Solides (CNRS UMR 8502), Bâtiment 510, Université Paris-Sud/Université Paris-Saclay, 91405 Orsay, France
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21
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Quantum spins and hybridization in artificially-constructed chains of magnetic adatoms on a superconductor. Nat Commun 2022; 13:2160. [PMID: 35443753 PMCID: PMC9021194 DOI: 10.1038/s41467-022-29879-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/01/2022] [Indexed: 11/09/2022] Open
Abstract
Magnetic adatom chains on surfaces constitute fascinating quantum spin systems. Superconducting substrates suppress interactions with bulk electronic excitations but couple the adatom spins to a chain of subgap Yu-Shiba-Rusinov (YSR) quasiparticles. Using a scanning tunneling microscope, we investigate such correlated spin-fermion systems by constructing Fe chains adatom by adatom on superconducting NbSe2. The adatoms couple entirely via the substrate, retaining their quantum spin nature. In dimers, we observe that the deepest YSR state undergoes a quantum phase transition due to Ruderman-Kittel-Kasuya-Yosida interactions, a distinct signature of quantum spins. Chains exhibit coherent hybridization and band formation of the YSR excitations, indicating ferromagnetic coupling. Longer chains develop separate domains due to coexisting charge-density-wave order of NbSe2. Despite the spin-orbit-coupled substrate, we find no signatures of Majoranas, possibly because quantum spins reduce the parameter range for topological superconductivity. We suggest that adatom chains are versatile systems for investigating correlated-electron physics and its interplay with topological superconductivity. Previous studies of magnetic adatom chains on superconducting substrates have mostly focused on the regime of dense chains and classical spins. Here, using scanning tunnelling microscopy, the authors study the excitation spectra of Fe chains on a NbSe2 surface, adatom by adatom, in the regime of quantum spins.
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22
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Moreno-Da Silva S, Martínez JI, Develioglu A, Nieto-Ortega B, de Juan-Fernández L, Ruiz-Gonzalez L, Picón A, Oberli S, Alonso PJ, Moonshiram D, Pérez EM, Burzurí E. Magnetic, Mechanically Interlocked Porphyrin-Carbon Nanotubes for Quantum Computation and Spintronics. J Am Chem Soc 2021; 143:21286-21293. [PMID: 34825564 DOI: 10.1021/jacs.1c07058] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Atomic-scale reproducibility and tunability endorse magnetic molecules as candidates for spin qubits and spintronics. A major challenge is to implant those molecular spins into circuit geometries that may allow one, two, or a few spins to be addressed in a controlled way. Here, the formation of mechanically bonded, magnetic porphyrin dimeric rings around carbon nanotubes (mMINTs) is presented. The mechanical bond places the porphyrin magnetic cores in close contact with the carbon nanotube without disturbing their structures. A combination of spectroscopic techniques shows that the magnetic geometry of the dimers is preserved upon formation of the macrocycle and the mMINT. Moreover, the metallic core selection determines the spin location in the mMINT. The suitability of mMINTs as qubits is explored by measuring their quantum coherence times (Tm). Formation of the dimeric ring preserves the Tm found in the monomer, which remains in the μs scale for mMINTs. The carbon nanotube is used as vessel to place the molecules in complex circuits. This strategy can be extended to other families of magnetic molecules. The size and composition of the macrocycle can be tailored to modulate magnetic interactions between the cores and to introduce magnetic asymmetries (heterometallic dimers) for more complex molecule-based qubits.
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Affiliation(s)
| | - Jesús I Martínez
- Instituto de Nanociencia y Materiales de Aragón (INMA), Universidad de Zaragoza and CSIC, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Aysegul Develioglu
- IMDEA Nanociencia, Campus de Cantoblanco, Calle Faraday 9, 28049 Madrid, Spain
| | - Belén Nieto-Ortega
- IMDEA Nanociencia, Campus de Cantoblanco, Calle Faraday 9, 28049 Madrid, Spain
| | | | - Luisa Ruiz-Gonzalez
- Departamento de Química Inorgánica, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Antonio Picón
- Departamento de Química, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Soléne Oberli
- Departamento de Química, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Pablo J Alonso
- Instituto de Nanociencia y Materiales de Aragón (INMA), Universidad de Zaragoza and CSIC, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Dooshaye Moonshiram
- IMDEA Nanociencia, Campus de Cantoblanco, Calle Faraday 9, 28049 Madrid, Spain
| | - Emilio M Pérez
- IMDEA Nanociencia, Campus de Cantoblanco, Calle Faraday 9, 28049 Madrid, Spain
| | - Enrique Burzurí
- IMDEA Nanociencia, Campus de Cantoblanco, Calle Faraday 9, 28049 Madrid, Spain.,Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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23
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Heinrich AJ, Oliver WD, Vandersypen LMK, Ardavan A, Sessoli R, Loss D, Jayich AB, Fernandez-Rossier J, Laucht A, Morello A. Quantum-coherent nanoscience. NATURE NANOTECHNOLOGY 2021; 16:1318-1329. [PMID: 34845333 DOI: 10.1038/s41565-021-00994-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 09/01/2021] [Indexed: 05/25/2023]
Abstract
For the past three decades nanoscience has widely affected many areas in physics, chemistry and engineering, and has led to numerous fundamental discoveries, as well as applications and products. Concurrently, quantum science and technology has developed into a cross-disciplinary research endeavour connecting these same areas and holds burgeoning commercial promise. Although quantum physics dictates the behaviour of nanoscale objects, quantum coherence, which is central to quantum information, communication and sensing, has not played an explicit role in much of nanoscience. This Review describes fundamental principles and practical applications of quantum coherence in nanoscale systems, a research area we call quantum-coherent nanoscience. We structure this Review according to specific degrees of freedom that can be quantum-coherently controlled in a given nanoscale system, such as charge, spin, mechanical motion and photons. We review the current state of the art and focus on outstanding challenges and opportunities unlocked by the merging of nanoscience and coherent quantum operations.
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Affiliation(s)
- Andreas J Heinrich
- Center for Quantum Nanoscience (QNS), Institute for Basic Science, Seoul, Korea.
- Physics Department, Ewha Womans University, Seoul, Korea.
| | - William D Oliver
- Department of Electrical Engineering and Computer Science, and Department of Physics, MIT, Cambridge, MA, USA
- Lincoln Laboratory, MIT, Lexington, MA, USA
| | | | - Arzhang Ardavan
- CAESR, The Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Roberta Sessoli
- Department of Chemistry 'U. Schiff' & INSTM, University of Florence, Sesto Fiorentino, Italy
| | - Daniel Loss
- Department of Physics, University of Basel, Basel, Switzerland
| | | | - Joaquin Fernandez-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- Departamento de Física Aplicada, Universidad de Alicante, Alicante, Spain
| | - Arne Laucht
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia
| | - Andrea Morello
- School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney, New South Wales, Australia.
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24
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Chicco S, Chiesa A, Allodi G, Garlatti E, Atzori M, Sorace L, De Renzi R, Sessoli R, Carretta S. Controlled coherent dynamics of [VO(TPP)], a prototype molecular nuclear qudit with an electronic ancilla. Chem Sci 2021; 12:12046-12055. [PMID: 34667570 PMCID: PMC8457369 DOI: 10.1039/d1sc01358k] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 08/02/2021] [Indexed: 01/06/2023] Open
Abstract
We show that [VO(TPP)] (vanadyl tetraphenylporphyrinate) is a promising system to implement quantum computation algorithms based on encoding information in multi-level (qudit) units. Indeed, it embeds a nuclear spin 7/2 coupled to an electronic spin 1/2 by hyperfine interaction. This qubit-qudit unit can be exploited to implement quantum error correction and quantum simulation algorithms. Through a combined theoretical and broadband nuclear magnetic resonance study, we demonstrate that the elementary operations of such algorithms can be efficiently implemented on the nuclear spin qudit. Manipulation of the nuclear qudit can be achieved by resonant radio-frequency pulses, thanks to the remarkably long coherence times and the effective quadrupolar coupling induced by the strong hyperfine interaction. This approach may open new perspectives for developing new molecular qubit-qudit systems.
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Affiliation(s)
- Simone Chicco
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
- UdR Parma, INSTM I-43124 Parma Italy
| | - Alessandro Chiesa
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
- UdR Parma, INSTM I-43124 Parma Italy
| | - Giuseppe Allodi
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
| | - Elena Garlatti
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
- UdR Parma, INSTM I-43124 Parma Italy
| | - Matteo Atzori
- Dipartimento di Chimica "Ugo Schiff" & INSTM, Università Degli Studi di Firenze I-50019 Sesto Fiorentino Italy
- Laboratoire National des Champs Magnétiques Intenses (LNCMI), Univ. Grenoble Alpes, INSA Toulouse, Univ. Toulouse Paul Sabatier, EMFL, CNRS F-38043 Grenoble France
| | - Lorenzo Sorace
- Dipartimento di Chimica "Ugo Schiff" & INSTM, Università Degli Studi di Firenze I-50019 Sesto Fiorentino Italy
| | - Roberto De Renzi
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
| | - Roberta Sessoli
- Dipartimento di Chimica "Ugo Schiff" & INSTM, Università Degli Studi di Firenze I-50019 Sesto Fiorentino Italy
| | - Stefano Carretta
- Università di Parma, Dipartimento di Scienze Matematiche, Fisiche e Informatiche I-43124 Parma Italy
- UdR Parma, INSTM I-43124 Parma Italy
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25
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Kamlapure A, Cornils L, Žitko R, Valentyuk M, Mozara R, Pradhan S, Fransson J, Lichtenstein AI, Wiebe J, Wiesendanger R. Correlation of Yu-Shiba-Rusinov States and Kondo Resonances in Artificial Spin Arrays on an s-Wave Superconductor. NANO LETTERS 2021; 21:6748-6755. [PMID: 34351781 PMCID: PMC8392378 DOI: 10.1021/acs.nanolett.1c00387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Mutually interacting magnetic atoms coupled to a superconductor have gained enormous interest due to their potential for the realization of topological superconductivity. Individual magnetic impurities produce states within the superconducting energy gap known as Yu-Shiba-Rusinov (YSR) states. Here, using the tip of a scanning tunneling microscope, we artificially craft spin arrays consisting of an Fe adatom interacting with an assembly of interstitial Fe atoms (IFA) on a superconducting oxygen-reconstructed Ta(100) surface and show that the magnetic interaction between the adatom and the IFA assembly can be tuned by adjusting the number of IFAs in the assembly. The YSR state experiences a characteristic crossover in its energetic position and particle-hole spectral weight asymmetry when the Kondo resonance shows spectral depletion around the Fermi energy. By the help of slave-boson mean-field theory (SBMFT) and numerical renormalization group (NRG) calculations we associate the crossover with the transition from decoupled Kondo singlets to an antiferromagnetic ground state of the Fe adatom spin and the IFA assembly effective spin.
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Affiliation(s)
- Anand Kamlapure
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - Lasse Cornils
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - Rok Žitko
- Jožef
Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska
19, SI-1000 Ljubljana, Slovenia
| | - Maria Valentyuk
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
- Department
of Theoretical Physics and Applied Mathematics, Ural Federal University, 19 Mira Street, Yekaterinburg 620002, Russia
| | - Roberto Mozara
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - Saurabh Pradhan
- Department
of Physics and Astronomy, Uppsala University, P.O. Box 516, Uppsala SE-751 21, Sweden
| | - Jonas Fransson
- Department
of Physics and Astronomy, Uppsala University, P.O. Box 516, Uppsala SE-751 21, Sweden
| | - Alexander I. Lichtenstein
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
- Department
of Theoretical Physics and Applied Mathematics, Ural Federal University, 19 Mira Street, Yekaterinburg 620002, Russia
| | - Jens Wiebe
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
| | - Roland Wiesendanger
- Department
of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany
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26
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Briganti M, Totti F. Magnetic anisotropy on demand exploiting high-pressure as remote control: an ab initio proof of concept. Dalton Trans 2021; 50:10621-10628. [PMID: 34286784 DOI: 10.1039/d1dt01719e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lanthanide based single molecule magnets have recently become very promising systems for creating single molecule devices working at high temperatures (nitrogen boiling temperature). However, the variation of the direction of the anisotropy tensor as a function of the applied pressure still represents a quite unexplored field. Application of external pressure can be a promising method toward neat control of magnetic anisotropy and relaxation processes in the bulk phase. Required criteria for being eligible for such systems are as follows: the presence of first excited energy levels with significantly different orientations of its anisotropy tensor; sufficiently low energies of such levels so that they can mix with the ground state; and the possibility of tuning their energies by small geometrical perturbations. The archetype compound {Na[DyDOTA(H2O)]·4H2O} (1) (H4DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-N,N',N'',N'''-tetraacetic acid) fulfils all such criteria. A state-of-the-art in silico proof of concept study on the possibility of controlling the orientation of the anisotropy tensor as a function of pressure in [DyDOTA(H2O)]- by inducing different apical water molecule (AWM) orientations and/or DOTA-induced crystal field is presented.
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Affiliation(s)
- Matteo Briganti
- Department of Chemistry "U. Schiff" and INSTM UdR Firenze, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Federico Totti
- Department of Chemistry "U. Schiff" and INSTM UdR Firenze, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
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27
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Mier C, Verlhac B, Garnier L, Robles R, Limot L, Lorente N, Choi DJ. Superconducting Scanning Tunneling Microscope Tip to Reveal Sub-millielectronvolt Magnetic Energy Variations on Surfaces. J Phys Chem Lett 2021; 12:2983-2989. [PMID: 33730501 DOI: 10.1021/acs.jpclett.1c00328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Combining the complex ordering ability of molecules with their local magnetic properties is a little-explored technique to tailor spin structures on surfaces. However, revealing the molecular geometry can be demanding. Nickelocene (Nc) molecules present a large spin-flip excitation leading to clear changes of conductance at the excitation-threshold bias. Using a superconducting tip, we have the energy resolution to detect small shifts of the Nc spin-flip excitation thresholds, permitting us to reveal the different individual environments of Nc molecules in an ordered layer. This knowledge allows us to reveal the adsorption configuration of a complex molecular structure formed by Nc molecules in different orientations and positions. As a consequence, we infer that Nc layers present a strong noncollinear magnetic-moment arrangement.
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Affiliation(s)
- Cristina Mier
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Benjamin Verlhac
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Léo Garnier
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Roberto Robles
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Laurent Limot
- Université de Strasbourg CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Nicolás Lorente
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
| | - Deung-Jang Choi
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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28
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Fan P, Yang F, Qian G, Chen H, Zhang YY, Li G, Huang Z, Xing Y, Kong L, Liu W, Jiang K, Shen C, Du S, Schneeloch J, Zhong R, Gu G, Wang Z, Ding H, Gao HJ. Observation of magnetic adatom-induced Majorana vortex and its hybridization with field-induced Majorana vortex in an iron-based superconductor. Nat Commun 2021; 12:1348. [PMID: 33649307 PMCID: PMC7921435 DOI: 10.1038/s41467-021-21646-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 02/05/2021] [Indexed: 11/09/2022] Open
Abstract
Braiding Majorana zero modes is essential for fault-tolerant topological quantum computing. Iron-based superconductors with nontrivial band topology have recently emerged as a surprisingly promising platform for creating distinct Majorana zero modes in magnetic vortices in a single material and at relatively high temperatures. The magnetic field-induced Abrikosov vortex lattice makes it difficult to braid a set of Majorana zero modes or to study the coupling of a Majorana doublet due to overlapping wave functions. Here we report the observation of the proposed quantum anomalous vortex with integer quantized vortex core states and the Majorana zero mode induced by magnetic Fe adatoms deposited on the surface. We observe its hybridization with a nearby field-induced Majorana vortex in iron-based superconductor FeTe0.55Se0.45. We also observe vortex-free Yu-Shiba-Rusinov bound states at the Fe adatoms with a weaker coupling to the substrate, and discover a reversible transition between Yu-Shiba-Rusinov states and Majorana zero mode by manipulating the exchange coupling strength. The dual origin of the Majorana zero modes, from magnetic adatoms and external magnetic field, provides a new single-material platform for studying their interactions and braiding in superconductors bearing topological band structures.
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Affiliation(s)
- Peng Fan
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Fazhi Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Guojian Qian
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Hui Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Yu-Yang Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
| | - Geng Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
| | - Zihao Huang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yuqing Xing
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lingyuan Kong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wenyao Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kun Jiang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Department of Physics, Boston College, Boston, MA, USA
| | - Chengmin Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
| | - Shixuan Du
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
| | - John Schneeloch
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Ruidan Zhong
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Genda Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Ziqiang Wang
- Department of Physics, Boston College, Boston, MA, USA.
| | - Hong Ding
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China.
| | - Hong-Jun Gao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China.
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29
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Wang D, Wiebe J, Zhong R, Gu G, Wiesendanger R. Spin-Polarized Yu-Shiba-Rusinov States in an Iron-Based Superconductor. PHYSICAL REVIEW LETTERS 2021; 126:076802. [PMID: 33666492 DOI: 10.1103/physrevlett.126.076802] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/21/2021] [Indexed: 05/06/2023]
Abstract
Yu-Shiba-Rusinov (YSR) bound states appear when a magnetic atom interacts with a superconductor. Here, we report on spin-resolved spectroscopic studies of YSR states related with Fe atoms deposited on the surface of the topological superconductor FeTe_{0.55}Se_{0.45} using a spin-polarized scanning tunneling microscope. We clearly identify the spin signature of pairs of YSR bound states at finite energies within the superconducting gap having opposite spin polarization as theoretically predicted. In addition, we also observe zero-energy bound states for some of the adsorbed Fe atoms. In this case, a spin signature is found to be absent indicating the absence of Majorana bound states associated with Fe adatoms on FeTe_{0.55}Se_{0.45}.
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Affiliation(s)
- Dongfei Wang
- Department of Physics, University of Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
| | - Jens Wiebe
- Department of Physics, University of Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
| | - Ruidan Zhong
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Genda Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Roland Wiesendanger
- Department of Physics, University of Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
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30
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Li Z, Wu Q, Wu C. Surface/Interface Chemistry Engineering of Correlated-Electron Materials: From Conducting Solids, Phase Transitions to External-Field Response. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002807. [PMID: 33643796 PMCID: PMC7887576 DOI: 10.1002/advs.202002807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/25/2020] [Indexed: 06/12/2023]
Abstract
Correlated electronic materials (CEMs) with strong electron-electron interactions are often associated with exotic properties, such as metal-insulator transition (MIT), charge density wave (CDW), superconductivity, and magnetoresistance (MR), which are fundamental to next generation condensed matter research and electronic devices. When the dimension of CEMs decreases, exposing extremely high specific surface area and enhancing electronic correlation, the surface states are equally important to the bulk phase. Therefore, surface/interface chemical interactions provide an alternative route to regulate the intrinsic properties of low-dimensional CEMs. Here, recent achievements in surface/interface chemistry engineering of low-dimensional CEMs are reviewed, using surface modification, molecule-solid interaction, and interface electronic coupling, toward modulation of conducting solids, phase transitions including MIT, CDW, superconductivity, and magnetism transition, as well as external-field response. Surface/interface chemistry engineering provides a promising strategy for exploring novel properties and functional applications in low-dimensional CEMs. Finally, the current challenge and outlook of the surface/interface engineering are also pointed out for future research development.
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Affiliation(s)
- Zejun Li
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
| | - Qiran Wu
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
| | - Changzheng Wu
- Hefei National Laboratory for Physical Sciences at the MicroscaleCAS center for Excellence in Nanoscienceand CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefeiAnhui230026PR China
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31
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Chatzopoulos D, Cho D, Bastiaans KM, Steffensen GO, Bouwmeester D, Akbari A, Gu G, Paaske J, Andersen BM, Allan MP. Spatially dispersing Yu-Shiba-Rusinov states in the unconventional superconductor FeTe 0.55Se 0.45. Nat Commun 2021; 12:298. [PMID: 33436594 PMCID: PMC7804303 DOI: 10.1038/s41467-020-20529-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023] Open
Abstract
By using scanning tunneling microscopy (STM) we find and characterize dispersive, energy-symmetric in-gap states in the iron-based superconductor FeTe0.55Se0.45, a material that exhibits signatures of topological superconductivity, and Majorana bound states at vortex cores or at impurity locations. We use a superconducting STM tip for enhanced energy resolution, which enables us to show that impurity states can be tuned through the Fermi level with varying tip-sample distance. We find that the impurity state is of the Yu-Shiba-Rusinov (YSR) type, and argue that the energy shift is caused by the low superfluid density in FeTe0.55Se0.45, which allows the electric field of the tip to slightly penetrate the sample. We model the newly introduced tip-gating scenario within the single-impurity Anderson model and find good agreement to the experimental data.
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Affiliation(s)
- Damianos Chatzopoulos
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
| | - Doohee Cho
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands ,grid.15444.300000 0004 0470 5454Department of Physics, Yonsei University, Seoul, 03722 Republic of Korea
| | - Koen M. Bastiaans
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
| | - Gorm O. Steffensen
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Damian Bouwmeester
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands ,grid.5292.c0000 0001 2097 4740Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, CJ 2628 Netherlands
| | - Alireza Akbari
- grid.419507.e0000 0004 0491 351XMax Planck Institute for the Chemical Physics of Solids, Dresden, D-01187 Germany ,grid.49100.3c0000 0001 0742 4007Max Planck POSTECH Center for Complex Phase Materials, and Department of Physics, POSTECH, Pohang, Gyeongbuk 790-784 Korea
| | - Genda Gu
- grid.202665.50000 0001 2188 4229Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Jens Paaske
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Brian M. Andersen
- grid.5254.60000 0001 0674 042XCenter for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen Ø, 2100 Denmark
| | - Milan P. Allan
- grid.5132.50000 0001 2312 1970Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, CA 2333 The Netherlands
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32
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Rubio-Verdú C, Zaldívar J, Žitko R, Pascual JI. Coupled Yu-Shiba-Rusinov States Induced by a Many-Body Molecular Spin on a Superconductor. PHYSICAL REVIEW LETTERS 2021; 126:017001. [PMID: 33480757 DOI: 10.1103/physrevlett.126.017001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
A magnetic impurity on a superconductor induces Yu-Shiba-Rusinov (YSR) bound states, detected by tunneling spectroscopy as long-lived quasiparticle excitations inside the superconducting gap. Coupled YSR states constitute basic elements to engineer artificial superconducting states, but their substrate-mediated interactions are generally weak. In this Letter, we report that intramolecular (Hund's-like) exchange interactions produce coupled YSR states across a molecular platform. We measured YSR spectra along a magnetic iron-porphyrin on Pb(111) and found evidence of two distinct interaction channels, which invert their particle-hole asymmetry across the molecule. Numerical calculations show that the identical YSR asymmetry pattern of the two channels is caused by two spin-hosting orbitals with opposite potential scattering and coupled strongly. Both channels can be similarly excited by tunneling electrons into each orbital, depicting a new scenario for entangled superconducting bound states using molecular platforms.
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Affiliation(s)
- Carmen Rubio-Verdú
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Department of Physics, Columbia University, New York, New York 10027, United States
| | | | - Rok Žitko
- Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia
| | - Jose Ignacio Pascual
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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33
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Santanni F, Albino A, Atzori M, Ranieri D, Salvadori E, Chiesa M, Lunghi A, Bencini A, Sorace L, Totti F, Sessoli R. Probing Vibrational Symmetry Effects and Nuclear Spin Economy Principles in Molecular Spin Qubits. Inorg Chem 2021; 60:140-151. [PMID: 33305944 PMCID: PMC7872321 DOI: 10.1021/acs.inorgchem.0c02573] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Indexed: 12/18/2022]
Abstract
The selection of molecular spin qubits with a long coherence time, Tm, is a central task for implementing molecule-based quantum technologies. Even if a sufficiently long Tm can be achieved through an efficient synthetic strategy and ad hoc experimental measurement procedures, many factors contributing to the loss of coherence still need to be thoroughly investigated and understood. Vibrational properties and nuclear spins of hydrogens are two of them. The former plays a paramount role, but a detailed theoretical investigation aimed at studying their effects on the spin dynamics of molecular complexes such as the benchmark phthalocyanine (Pc) is still missing, whereas the effect of the latter deserves to be examined in detail for such a class of compounds. In this work, we adopted a combined theoretical and experimental approach to investigate the relaxation properties of classical [Cu(Pc)] and a CuII complex based on the ligand tetrakis(thiadiazole)porphyrazine (H2TTDPz), characterized by a hydrogen-free molecular structure. Systematic calculations of molecular vibrations exemplify the effect of normal modes on the spin-lattice relaxation process, unveiling a different contribution to T1 depending on the symmetry of normal modes. Moreover, we observed that an appreciable Tm enhancement could be achieved by removing hydrogens from the ligand.
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Affiliation(s)
- Fabio Santanni
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Andrea Albino
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Matteo Atzori
- Laboratoire
National des Champs Magnétiques Intenses (LNCMI), Univ. Grenoble
Alpes, INSA Toulouse, Univ. Toulouse Paul
Sabatier, EMFL, CNRS, F38043 Grenoble, France
| | - Davide Ranieri
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Enrico Salvadori
- Dipartimento
di Chimica e NIS Centre, Università
di Torino, Via P. Giuria 7, I10125 Torino, Italy
| | - Mario Chiesa
- Dipartimento
di Chimica e NIS Centre, Università
di Torino, Via P. Giuria 7, I10125 Torino, Italy
| | - Alessandro Lunghi
- School
of Physics, AMBER and CRANN Institute, Trinity
College, Dublin 2, Ireland
| | - Andrea Bencini
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Lorenzo Sorace
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Federico Totti
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
| | - Roberta Sessoli
- Dipartimento
di Chimica “Ugo Schiff” & INSTM RU, Università degli Studi di Firenze, Via della Lastruccia 3, I50019 Sesto Fiorentino, Firenze) Italy
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34
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Homberg J, Weismann A, Berndt R, Gruber M. Inducing and Controlling Molecular Magnetism through Supramolecular Manipulation. ACS NANO 2020; 14:17387-17395. [PMID: 33225694 DOI: 10.1021/acsnano.0c07574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Diamagnetic H2 phthalocyanine molecules are probed on superconducting Pb(100) using a low-temperature scanning tunneling micoscope (STM). In supramolecular arrays made with the STM, the molecules acquire a spin as detected via the emergence of Yu-Shiba-Rusinov resonances. The spin moments vary among the molecules and are determined by the electrostatic field that results from polar bonds in the surrounding Pc molecules. The moments are further finely tuned by repositioning the hydrogen atoms of the inner macrocycle of the surrounding molecules.
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Affiliation(s)
- Jan Homberg
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
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35
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Farinacci L, Ahmadi G, Ruby M, Reecht G, Heinrich BW, Czekelius C, von Oppen F, Franke KJ. Interfering Tunneling Paths through Magnetic Molecules on Superconductors: Asymmetries of Kondo and Yu-Shiba-Rusinov Resonances. PHYSICAL REVIEW LETTERS 2020; 125:256805. [PMID: 33416394 DOI: 10.1103/physrevlett.125.256805] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/10/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
Magnetic adsorbates on superconductors induce a Kondo resonance outside and Yu-Shiba-Rusinov (YSR) bound states inside the superconducting energy gap. When probed by scanning tunneling spectroscopy, the associated differential-conductance spectra frequently exhibit characteristic bias-voltage asymmetries. Here, we observe correlated variations of Kondo and YSR asymmetries across an Fe-porphyrin molecule adsorbed on Pb(111). We show that both asymmetries originate in interfering tunneling paths via a spin-carrying orbital and the highest occupied molecular orbital (HOMO). Strong evidence for this model comes from nodal planes of the HOMO, where tunneling reveals symmetric Kondo and YSR resonances. Our results establish an important mechanism for the asymmetries of Kondo and YSR line shapes.
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Affiliation(s)
- Laëtitia Farinacci
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Gelavizh Ahmadi
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Michael Ruby
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Gaël Reecht
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Benjamin W Heinrich
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Constantin Czekelius
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225Düsseldorf, Germany
| | - Felix von Oppen
- Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Katharina J Franke
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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36
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Manipulation of Molecular Spin State on Surfaces Studied by Scanning Tunneling Microscopy. NANOMATERIALS 2020; 10:nano10122393. [PMID: 33266045 PMCID: PMC7761235 DOI: 10.3390/nano10122393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022]
Abstract
The adsorbed magnetic molecules with tunable spin states have drawn wide attention for their immense potential in the emerging fields of molecular spintronics and quantum computing. One of the key issues toward their application is the efficient controlling of their spin state. This review briefly summarizes the recent progress in the field of molecular spin state manipulation on surfaces. We focus on the molecular spins originated from the unpaired electrons of which the Kondo effect and spin excitation can be detected by scanning tunneling microscopy and spectroscopy (STM and STS). Studies of the molecular spin-carriers in three categories are overviewed, i.e., the ones solely composed of main group elements, the ones comprising 3d-metals, and the ones comprising 4f-metals. Several frequently used strategies for tuning molecular spin state are exemplified, including chemical reactions, reversible atomic/molecular chemisorption, and STM-tip manipulations. The summary of the successful case studies of molecular spin state manipulation may not only facilitate the fundamental understanding of molecular magnetism and spintronics but also inspire the design of the molecule-based spintronic devices and materials.
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37
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Gimeno I, Kersten W, Pallarés MC, Hermosilla P, Martínez-Pérez MJ, Jenkins MD, Angerer A, Sánchez-Azqueta C, Zueco D, Majer J, Lostao A, Luis F. Enhanced Molecular Spin-Photon Coupling at Superconducting Nanoconstrictions. ACS NANO 2020; 14:8707-8715. [PMID: 32441922 DOI: 10.1021/acsnano.0c03167] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We combine top-down and bottom-up nanolithography to optimize the coupling of small molecular spin ensembles to 1.4 GHz on-chip superconducting resonators. Nanoscopic constrictions, fabricated with a focused ion beam at the central transmission line, locally concentrate the microwave magnetic field. Drops of free-radical molecules have been deposited from solution onto the circuits. For the smallest ones, the molecules were delivered at the relevant circuit areas by means of an atomic force microscope. The number of spins Neff effectively coupled to each device was accurately determined combining Scanning Electron and Atomic Force Microscopies. The collective spin-photon coupling constant has been determined for samples with Neff ranging between 2 × 106 and 1012 spins, and for temperatures down to 44 mK. The results show the well-known collective enhancement of the coupling proportional to the square root of Neff. The average coupling of individual spins is enhanced by more than 4 orders of magnitude (from 4 mHz up to above 180 Hz), when the transmission line width is reduced from 400 μm down to 42 nm, and reaches maximum values near 1 kHz for molecules located on the smallest nanoconstrictions.
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Affiliation(s)
- Ignacio Gimeno
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Wenzel Kersten
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - María C Pallarés
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - Pablo Hermosilla
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - María José Martínez-Pérez
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Mark D Jenkins
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Andreas Angerer
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | | | - David Zueco
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Johannes Majer
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - Anabel Lostao
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Fernando Luis
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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38
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Aravena D, Ruiz E. Spin dynamics in single-molecule magnets and molecular qubits. Dalton Trans 2020; 49:9916-9928. [PMID: 32589181 DOI: 10.1039/d0dt01414a] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Over recent decades, much effort has been made to lengthen spin relaxation/decoherence times of single-molecule magnets and molecular qubits by following different chemical design rules such as maximizing the total spin value, controlling symmetry, enhancing the ligand field or inhibiting key vibrational modes. Simultaneously, electronic structure calculations have been employed to provide an understanding of the processes involved in the spin dynamics of molecular systems and served to refine or introduce new design rules. This review focuses on contemporary theoretical approaches focused on the calculation of spin relaxation/decoherence times, highlighting their main features and scope. Fundamental aspects of experimental techniques for the determination of key Single Molecule Magnet/Spin Qubit properties are also reviewed.
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Affiliation(s)
- Daniel Aravena
- Departamento de Química de los Materiales, Universidad de Santiago de Chile, Santiago 9170022, Chile
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39
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Arruda LM, Ali ME, Bernien M, Hatter N, Nickel F, Kipgen L, Hermanns CF, Bißwanger T, Loche P, Heinrich BW, Franke KJ, Oppeneer PM, Kuch W. Surface-orientation- and ligand-dependent quenching of the spin magnetic moment of Co porphyrins adsorbed on Cu substrates. Phys Chem Chem Phys 2020; 22:12688-12696. [PMID: 32458937 DOI: 10.1039/d0cp00854k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Porphyrin molecules are particularly interesting candidates for spintronic applications due to their bonding flexibility, which allows to modify their properties substantially by the addition or transformation of ligands. Here, we investigate the electronic and magnetic properties of cobalt octaethylporphyrin (CoOEP), deposited on copper substrates with two distinct crystallographic surface orientations, Cu(100) and Cu(111), with X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD). A significant magnetic moment is present in the Co ions of the molecules deposited on Cu(100), but it is completely quenched on Cu(111). Heating the molecules on both substrates to 500 K induces a ring-closure reaction with cobalt tetrabenzoporphyrin (CoTBP) as reaction product. In these molecules, the magnetic moment is quenched on both surfaces. Our XMCD and XAS measurements suggest that the filling of the dz2 orbital leads to a non-integer valence state and causes the quench of the spin moments on all samples except CoOEP/Cu(100), where the molecular conformation induces variations to the ligand field that lift the quench. We further employ density functional theory calculations, supplemented with on-site Coulomb correlations (DFT+U), to study the adsorption of these spin-bearing molecules on the Cu substrates. Our calculations show that charge transfer from the Cu substrates as well as charge redistribution within the Co 3d orbitals lead to the filling of the Co minority spin dz2 orbital, causing a 'turning off' of the exchange splitting and quenching of the spin moment at the Co magnetic centers. Our investigations suggest that, by this mechanism, molecule-substrate interactions can be used to control the quenching of the magnetic moments of the adsorbed molecules.
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Affiliation(s)
- Lucas M Arruda
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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40
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Malavolti L, McMurtrie G, Rolf-Pissarczyk S, Yan S, Burgess JAJ, Loth S. Minimally invasive spin sensing with scanning tunneling microscopy. NANOSCALE 2020; 12:11619-11626. [PMID: 32435779 DOI: 10.1039/c9nr10252c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Minimizing the invasiveness of scanning tunneling measurements is paramount for observation of the magnetic properties of unperturbed atomic-scale objects. We show that the invasiveness of STM inspection on few-atom spin systems can be drastically reduced by means of a remote detection scheme, which makes use of a sensor spin weakly coupled to the sensed object. By comparing direct and remote measurements we identify the relevant perturbations caused by the local probe. For direct inspection we find that tunneling electrons strongly perturb the investigated object even for currents as low as 3 pA. Electrons injected into the sensor spin induce perturbations with much reduced probability. The sensing scheme uses standard differential conductance measurements, and is decoupled both by its non-local nature, and by dynamic decoupling due to the significantly different time scales at which the sensor and sensed object evolve. The latter makes it possible to effectively remove static interactions between the sensed object and the spin sensor while still allowing the spin sensing. In this way we achieve measurements with a reduction in perturbative effects of up to 100 times relative to direct scanning tunneling measurements, which enables minimally invasive measurements of a few-atom magnet's fragile spin states with STM.
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Affiliation(s)
- Luigi Malavolti
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany. and Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Gregory McMurtrie
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany. and Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Steffen Rolf-Pissarczyk
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Shichao Yan
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany and School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jacob A J Burgess
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany and Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Sebastian Loth
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany. and Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany and Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
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41
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Serrano G, Poggini L, Briganti M, Sorrentino AL, Cucinotta G, Malavolti L, Cortigiani B, Otero E, Sainctavit P, Loth S, Parenti F, Barra AL, Vindigni A, Cornia A, Totti F, Mannini M, Sessoli R. Quantum dynamics of a single molecule magnet on superconducting Pb(111). NATURE MATERIALS 2020; 19:546-551. [PMID: 32066930 DOI: 10.1038/s41563-020-0608-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
Magnetic materials interfaced with superconductors may reveal new physical phenomena with potential for quantum technologies. The use of molecules as magnetic components has already shown great promise, but the diversity of properties offered by the molecular realm remains largely unexplored. Here we investigate a submonolayer of tetrairon(III) propeller-shaped single molecule magnets deposited on a superconducting lead surface. This material combination reveals a strong influence of the superconductor on the spin dynamics of the single molecule magnet. It is shown that the superconducting transition to the condensate state switches the single molecule magnet from a blocked magnetization state to a resonant quantum tunnelling regime. Our results open perspectives to control single molecule magnetism via superconductors and to use single molecule magnets as local probes of the superconducting state.
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Affiliation(s)
- Giulia Serrano
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy.
- Department of Industrial Engineering and INSTM Research Unit, University of Florence, Florence, Italy.
| | - Lorenzo Poggini
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
| | - Matteo Briganti
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
- Departamento de Química, Universidade Federal do Paraná, Curitiba, Brazil
| | - Andrea Luigi Sorrentino
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
- Department of Industrial Engineering and INSTM Research Unit, University of Florence, Florence, Italy
| | - Giuseppe Cucinotta
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
| | - Luigi Malavolti
- Institute FMQ, University of Stuttgart & Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - Brunetto Cortigiani
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
| | - Edwige Otero
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, France
| | - Philippe Sainctavit
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, France
- IMPMC, UMR7590 CNRS, Sorbonne Université, MNHN, Paris, France
| | - Sebastian Loth
- Institute FMQ, University of Stuttgart & Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - Francesca Parenti
- Department of Chemical and Geological Sciences and INSTM Research Unit, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | - Andrea Cornia
- Department of Chemical and Geological Sciences and INSTM Research Unit, University of Modena and Reggio Emilia, Modena, Italy
| | - Federico Totti
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
| | - Matteo Mannini
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy
| | - Roberta Sessoli
- Department of Chemistry 'Ugo Schiff' and INSTM Research Unit, University of Florence, Sesto Fiorentino, Italy.
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42
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Liebhaber E, Acero González S, Baba R, Reecht G, Heinrich BW, Rohlf S, Rossnagel K, von Oppen F, Franke KJ. Yu-Shiba-Rusinov States in the Charge-Density Modulated Superconductor NbSe 2. NANO LETTERS 2020; 20:339-344. [PMID: 31842547 DOI: 10.1021/acs.nanolett.9b03988] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
NbSe2 is a remarkable superconductor in which charge-density order coexists with pairing correlations at low temperatures. Here, we study the interplay of magnetic adatoms and their Yu-Shiba-Rusinov (YSR) bound states with the charge density order. Exploiting the incommensurate nature of the charge-density wave (CDW), our measurements provide a thorough picture of how the CDW affects both the energies and the wave functions of the YSR states. Key features of the dependence of the YSR states on adsorption site relative to the CDW are explained by model calculations. Several properties make NbSe2 a promising substrate for realizing topological nanostructures. Our results will be important in designing such systems.
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Affiliation(s)
| | | | | | | | | | - Sebastian Rohlf
- Ruprecht-Haensel-Labor and Institut für Experimentelle und Angewandte Physik , Christian-Albrechts-Universität zu Kiel , 24098 Kiel , Germany
| | - Kai Rossnagel
- Ruprecht-Haensel-Labor and Institut für Experimentelle und Angewandte Physik , Christian-Albrechts-Universität zu Kiel , 24098 Kiel , Germany
- Deutsches Elektronen-Synchrotron DESY , 22607 Hamburg , Germany
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43
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Jackson CE, Lin CY, van Tol J, Zadrozny JM. Orientation dependence of phase memory relaxation in the V(IV) ion at high frequencies. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.137034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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44
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Kalinke LHG, Cangussu D, Mon M, Bruno R, Tiburcio E, Lloret F, Armentano D, Pardo E, Ferrando-Soria J. Metal-Organic Frameworks as Playgrounds for Reticulate Single-Molecule Magnets. Inorg Chem 2019; 58:14498-14506. [PMID: 31621305 DOI: 10.1021/acs.inorgchem.9b02086] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Achieving fine control on the structure of metal-organic frameworks (MOFs) is mandatory to obtain target physical properties. Herein, we present how the combination of a metalloligand approach and a postsynthetic method is a suitable and highly useful synthetic strategy to success on this extremely difficult task. First, a novel oxamato-based tetranuclear cobalt(III) compound with a tetrahedron-shaped geometry is used, for the first time, as the metalloligand toward calcium(II) metal ions to lead to a diamagnetic CaII-CoIII three-dimensional (3D) MOF (1). In a second stage, in a single-crystal-to-single-crystal manner, the calcium(II) ions are replaced by terbium(III), dysprosium(III), holmium(III), and erbium(III) ions to yield four isostructural novel LnIII-CoIII [Ln = Tb (2), Dy (3), Ho (4), and Er (5)] 3D MOFs. Direct-current magnetic properties for 2-5 show typical performances for the ground-state terms of the lanthanoid cations [7F6 (TbIII), 6H15/2 (DyIII), 5I8 (HoIII), and 4I15/2 (ErIII)]. Analysis of the χMT data indicates that the ground state is the lowest MJ value, that is, MJ = 0 (2 and 4) and ±1/2 (3 and 5). Kramers' ions (3 and 5) exhibit field-induced emergent frequency-dependent alternating-current magnetic susceptibility signals, which is indicative of the presence of slow magnetic relaxation typical of single-molecule magnets.
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Affiliation(s)
- Lucas H G Kalinke
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain.,Instituto Federal de Goiás , 75131-457 , Anápolis , Goiás Brazil.,Instituto de Química , Universidade Federal de Goiás , 74690-900 , Goiânia , Goiás Brazil
| | - Danielle Cangussu
- Instituto de Química , Universidade Federal de Goiás , 74690-900 , Goiânia , Goiás Brazil
| | - Marta Mon
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain
| | - Rosaria Bruno
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Rende 87036 , Cosenza , Italy
| | - Estefania Tiburcio
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain
| | - Francesc Lloret
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain
| | - Donatella Armentano
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Rende 87036 , Cosenza , Italy
| | - Emilio Pardo
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain
| | - Jesus Ferrando-Soria
- Departament de Química Inorgànica, Instituto de Ciencia Molecular , Universitat de València , 46980 Paterna , València , Spain
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45
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Kezilebieke S, Žitko R, Dvorak M, Ojanen T, Liljeroth P. Observation of Coexistence of Yu-Shiba-Rusinov States and Spin-Flip Excitations. NANO LETTERS 2019; 19:4614-4619. [PMID: 31251066 PMCID: PMC6628613 DOI: 10.1021/acs.nanolett.9b01583] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 06/05/2019] [Indexed: 06/09/2023]
Abstract
We investigate the spectral evolution in different metal phthalocyanine molecules on NbSe2 surface using scanning tunnelling microscopy (STM) as a function of the coupling with the substrate. For manganese phthalocyanine (MnPc), we demonstrate a smooth spectral crossover from Yu-Shiba-Rusinov (YSR) bound states to spin-flip excitations. This has not been observed previously and it is in contrast to simple theoretical expectations. We corroborate the experimental findings using numerical renormalization group calculations. Our results provide fundamental new insight on the behavior of atomic scale magnetic/SC hybrid systems, which is important, for example, for engineered topological superconductors and spin logic devices.
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Affiliation(s)
| | - Rok Žitko
- Jožef
Stefan Institute, Jamova 39, SI-1001 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska
19, SI-1000 Ljubljana, Slovenia
| | - Marc Dvorak
- Department
of Applied Physics, Aalto University School
of Science, 00076 Aalto, Finland
| | - Teemu Ojanen
- Department
of Applied Physics, Aalto University School
of Science, 00076 Aalto, Finland
- Computational
Physics Laboratory, Physics Unit, Faculty of Engineering and Natural
Sciences, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Peter Liljeroth
- Department
of Applied Physics, Aalto University School
of Science, 00076 Aalto, Finland
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46
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Atzori M, Sessoli R. The Second Quantum Revolution: Role and Challenges of Molecular Chemistry. J Am Chem Soc 2019; 141:11339-11352. [PMID: 31287678 DOI: 10.1021/jacs.9b00984] [Citation(s) in RCA: 193] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Implementation of modern Quantum Technologies might benefit from the remarkable quantum properties shown by molecular spin systems. In this Perspective, we highlight the role that molecular chemistry can have in the current second quantum revolution, i.e., the use of quantum physics principles to create new quantum technologies, in this specific case by means of molecular components. Herein, we briefly review the current status of the field by identifying the key advances recently made by the molecular chemistry community, such as for example the design of molecular spin qubits with long spin coherence and the realization of multiqubit architectures for quantum gates implementation. With a critical eye to the current state-of-the-art, we also highlight the main challenges needed for the further advancement of the field toward quantum technologies development.
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Affiliation(s)
- Matteo Atzori
- Laboratoire National des Champs Magnétiques Intenses, UPR 3228-CNRS , F-38042 Grenoble , France
| | - Roberta Sessoli
- Dipartimento di Chimica "Ugo Schiff" & INSTM RU , Università degli Studi di Firenze , I-50019 Sesto Fiorentino , Italy
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