1
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Kopteva NE, Yakovlev DR, Yalcin E, Akimov IA, Nestoklon MO, Glazov MM, Kotur M, Kudlacik D, Zhukov EA, Kirstein E, Hordiichuk O, Dirin DN, Kovalenko MV, Bayer M. Highly-Polarized Emission Provided by Giant Optical Orientation of Exciton Spins in Lead Halide Perovskite Crystals. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2403691. [PMID: 38884160 PMCID: PMC11336922 DOI: 10.1002/advs.202403691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/15/2024] [Indexed: 06/18/2024]
Abstract
Quantum technologic and spintronic applications require reliable material platforms that enable significant and long-living spin polarization of excitations, the ability to manipulate it optically in external fields, and the possibility to implement quantum correlations between spins, i.e., entanglement. Here it is demonstrated that these conditions are met in bulk crystals of lead halide perovskites. A giant optical orientation of 85% of excitons, approaching the ultimate limit of unity, in FA0.9Cs0.1PbI2.8Br0.2 crystals is reported. The exciton spin orientation is maintained during the exciton lifetime of 55 ps resulting in high circular polarization of the exciton emission. The optical orientation is robust to detuning of the excitation energy up to 0.3 eV above the exciton resonance and remains larger than 20% up to detunings of 0.9 eV. It evidences pure chiral selection rules and suppressed spin relaxation of electrons and holes, even with large kinetic energies. The exciton and electron-hole recombinations are distinguished by means of the spin dynamics detected via coherent spin quantum beats in magnetic field. Further, electron-hole spin correlations are demonstrated through linear polarization beats after circularly polarized excitation. These findings are supported by atomistic calculations. All-in-all, the results establish lead halide perovskite semiconductors as suitable platform for quantum technologies.
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Affiliation(s)
| | - Dmitri R. Yakovlev
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Eyüp Yalcin
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Ilya A. Akimov
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | | | - Mikhail M. Glazov
- Ioffe InstituteRussian Academy of SciencesSt. Petersburg194021Russia
| | - Mladen Kotur
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Dennis Kudlacik
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Evgeny A. Zhukov
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Erik Kirstein
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
| | - Oleh Hordiichuk
- Laboratory of Inorganic ChemistryDepartment of Chemistry and Applied BiosciencesETH ZürichZürichCH‐8093Switzerland
- Laboratory for Thin Films and PhotovoltaicsEmpa‐Swiss Federal Laboratories for Materials Science and TechnologyDübendorfCH‐8600Switzerland
| | - Dmitry N. Dirin
- Laboratory of Inorganic ChemistryDepartment of Chemistry and Applied BiosciencesETH ZürichZürichCH‐8093Switzerland
- Laboratory for Thin Films and PhotovoltaicsEmpa‐Swiss Federal Laboratories for Materials Science and TechnologyDübendorfCH‐8600Switzerland
| | - Maksym V. Kovalenko
- Laboratory of Inorganic ChemistryDepartment of Chemistry and Applied BiosciencesETH ZürichZürichCH‐8093Switzerland
- Laboratory for Thin Films and PhotovoltaicsEmpa‐Swiss Federal Laboratories for Materials Science and TechnologyDübendorfCH‐8600Switzerland
| | - Manfred Bayer
- Experimentelle Physik 2Technische Universität Dortmund44227DortmundGermany
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2
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Galler A, Rubio A, Neufeld O. Mapping Light-Dressed Floquet Bands by Highly Nonlinear Optical Excitations and Valley Polarization. J Phys Chem Lett 2023; 14:11298-11304. [PMID: 38063672 PMCID: PMC10749462 DOI: 10.1021/acs.jpclett.3c02936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/22/2023]
Abstract
Ultrafast nonlinear optical phenomena in solids have been attracting a great deal of interest as novel methodologies for the femtosecond spectroscopy of electron dynamics and control of the properties of materials. Here, we theoretically investigate strong-field nonlinear optical transitions in a prototypical two-dimensional material, hBN, and show that the k-resolved conduction band charge occupation patterns induced by an elliptically polarized laser can be understood in a multiphoton resonant picture, but, remarkably, only if using the Floquet light-dressed states instead of the undressed matter states. Our work demonstrates that Floquet dressing affects ultrafast charge dynamics and photoexcitation even from a single pump pulse and establishes a direct measurable signature for band dressing in nonlinear optical processes in solids, opening new paths for ultrafast spectroscopy and valley manipulation.
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Affiliation(s)
- Anna Galler
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - Angel Rubio
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
- Center
for Computational Quantum Physics, Flatiron
Institute, New York, New York 10010, United States
| | - Ofer Neufeld
- Max
Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
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3
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Nestoklon MO, Kirstein E, Yakovlev DR, Zhukov EA, Glazov MM, Semina MA, Ivchenko EL, Kolobkova EV, Kuznetsova MS, Bayer M. Tailoring the Electron and Hole Landé Factors in Lead Halide Perovskite Nanocrystals by Quantum Confinement and Halide Exchange. NANO LETTERS 2023; 23:8218-8224. [PMID: 37647545 DOI: 10.1021/acs.nanolett.3c02349] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The tunability of the optical properties of lead halide perovskite nanocrystals makes them highly appealing for applications. Halide anion exchange and quantum confinement enable tailoring of the band gap. For spintronics, the Landé g-factors of electrons and holes are essential. Using empirical tight-binding and k·p methods, we calculate them for nanocrystals of all-inorganic lead halide perovskites CsPbX3 (X = I, Br, Cl). The hole g-factor band gap dependence follows the universal law found for bulk perovskites, while for electrons, a considerable modification is predicted. Based on the k·p analysis, we conclude that this difference arises from the interaction of the bottom conduction band with the spin-orbit split electron states. These predictions are confirmed experimentally for electron and hole g-factors in CsPbI3 nanocrystals in a glass matrix, measured by time-resolved Faraday ellipticity in a magnetic field at cryogenic temperatures.
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Affiliation(s)
- Mikhail O Nestoklon
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Erik Kirstein
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Dmitri R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Evgeny A Zhukov
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Mikhail M Glazov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Marina A Semina
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | | | - Elena V Kolobkova
- ITMO University, 199034 St. Petersburg, Russia
- St. Petersburg State Institute of Technology, 190013 St. Petersburg, Russia
| | - Maria S Kuznetsova
- Spin Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Manfred Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
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4
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Barettin D, Sakharov AV, Tsatsulnikov AF, Nikolaev AE, Pecchia A, Auf der Maur M, Karpov SY, Cherkashin N. Impact of Local Composition on the Emission Spectra of InGaN Quantum-Dot LEDs. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1367. [PMID: 37110952 PMCID: PMC10145816 DOI: 10.3390/nano13081367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 06/19/2023]
Abstract
A possible solution for the realization of high-efficiency visible light-emitting diodes (LEDs) exploits InGaN-quantum-dot-based active regions. However, the role of local composition fluctuations inside the quantum dots and their effect of the device characteristics have not yet been examined in sufficient detail. Here, we present numerical simulations of a quantum-dot structure restored from an experimental high-resolution transmission electron microscopy image. A single InGaN island with the size of ten nanometers and nonuniform indium content distribution is analyzed. A number of two- and three-dimensional models of the quantum dot are derived from the experimental image by a special numerical algorithm, which enables electromechanical, continuum k→·p→, and empirical tight-binding calculations, including emission spectra prediction. Effectiveness of continuous and atomistic approaches are compared, and the impact of InGaN composition fluctuations on the ground-state electron and hole wave functions and quantum dot emission spectrum is analyzed in detail. Finally, comparison of the predicted spectrum with the experimental one is performed to assess the applicability of various simulation approaches.
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Affiliation(s)
- Daniele Barettin
- Department of Electronic Engineering, Università Niccoló Cusano, 00133 Rome, Italy
| | - Alexei V. Sakharov
- Ioffe Physico-Technical Institute RAS, 26 Polytekhnicheskaya str., 194021 St. Petersburg, Russia; (A.V.S.); (A.F.T.); (A.E.N.)
| | - Andrey F. Tsatsulnikov
- Ioffe Physico-Technical Institute RAS, 26 Polytekhnicheskaya str., 194021 St. Petersburg, Russia; (A.V.S.); (A.F.T.); (A.E.N.)
| | - Andrey E. Nikolaev
- Ioffe Physico-Technical Institute RAS, 26 Polytekhnicheskaya str., 194021 St. Petersburg, Russia; (A.V.S.); (A.F.T.); (A.E.N.)
| | | | - Matthias Auf der Maur
- Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy
| | - Sergey Yu. Karpov
- Soft-Impact, Ltd., P.O. Box 83, 27 Engels ave., 194156 St. Petersburg, Russia
| | - Nikolay Cherkashin
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse, CEDEX 4, France
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5
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De Leonardis F, Soref R. High-Performance Pockels Effect Modulation and Switching in Silicon-Based GaP/Si, AlP/Si, ZnS/Si, AlN/3C-SiC, GaAs/Ge, ZnSe/GaAs, and ZnSe/Ge Superlattice-On-Insulator Integrated Circuits. SENSORS (BASEL, SWITZERLAND) 2022; 22:7866. [PMID: 36298217 PMCID: PMC9607796 DOI: 10.3390/s22207866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
We propose new a Si-based waveguided Superlattice-on-Insulator (SLOI) platforms for high-performance electro-optical (EO) 2 × 2 and N × M switching and 1 × 1 modulation, including broad spectrum and resonant. We present a theoretical investigation based on the tight-binding Hamiltonian of the Pockels EO effect in the lattice-matched undoped (GaP)N/(Si2)M, (AlP)N/(Si2)M, (ZnS)N/(Si2)M, (AlN)N/(3C-SiC)M, (GaAs)N/(Ge2)M, (ZnSe)N/(GaAs)M, and (ZnSe)N/(Ge2)M wafer-scale short-period superlattices that are etched into waveguided networks of small-footprint Mach-Zehnder interferometers and micro-ring resonators to yield opto-electronic chips. The spectra of the Pockels r33 coefficient have been simulated as a function of the number of the atomic monolayers for "non-relaxed" heterointerfaces. The large obtained r33 values enable the SLOI circuit platforms to offer a very favorable combination of monolithic construction, cost-effective manufacturability, high modulation/switching speed, high information bandwidth, tiny footprint, low energy per bit, low switching voltage, near-IR-and-telecom wavelength coverage, and push-pull operation. By optimizing waveguide, clad, and electrode dimensions, we obtained very desirable values of the VπL performance metric, in the range of 0.062 to 0.275 V·cm, portending a bright future for a variety of applications, such as sensor networks or Internet of Things (IoT).
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Affiliation(s)
- Francesco De Leonardis
- Photonics Research Group, Department of Electrical and Information Engineering, Politecnico di Bari, Via Orabona 4, 70126 Bari, Italy
| | - Richard Soref
- Department of Engineering, University of Massachusetts at Boston, Boston, MA 02125, USA
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6
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Xie WW, Qian WR, Zhang YM. Far-field thermal radiation properties of graphene under uniaxial strain. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:435302. [PMID: 35985316 DOI: 10.1088/1361-648x/ac8b52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Electronic band structure and optical conductivity of single-layer graphene could be altered by applied uniaxial strain. Valley and space inversion symmetries are broken. Dirac cones are deformed. We investigate the effect of uniaxial strain on the radiative properties of graphene from the perspective of direction and modulus. Optical conductivity exhibits wealthy phenomenon due to the degeneracy of the energy band broken by strain. The total energy radiation exhibits a novel behavior of periodicity inθ, in accordance with the symmetry of the hexagonal honeycomb lattice.
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Affiliation(s)
- Wen-Wu Xie
- College of Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Wen-Ri Qian
- College of Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Yong-Mei Zhang
- College of Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
- Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT, Nanjing 211106, People's Republic of China
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7
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Du M, Liu X, Xie S. Spin-orbit coupling and the fine optical structure of chiral helical polymers. Phys Chem Chem Phys 2022; 24:9557-9563. [PMID: 35394001 DOI: 10.1039/d2cp01092e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With the discovery of the chiral-induced spin selectivity (CISS) effect, it has been recognized that spin and structural spin-orbit coupling (SOC) play important roles in the electro-optical properties of chiral materials. We redefine the spin-dependent current and magnetic moment operators to include chiral-induced SOC in a helical polymer and deduce optical absorption and circular dichroism (CD) formulae. The fine structure in the optical spectra is calculated for a helical polymer described with the tight-binding model. The effects of both the electron orbit and spin on the optical absorption and CD are discussed. Our investigations demonstrate that the synergy between the electron orbit and spin will contribute to higher-sensitivity circularly polarized light (CPL) detection.
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Affiliation(s)
- Mengzhao Du
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Ji'nan 250100, China.
| | - Xuan Liu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Ji'nan 250100, China.
| | - Shijie Xie
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Ji'nan 250100, China.
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8
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Jin G, Zheng D, He L. Calculation of Berry curvature using non-orthogonal atomic orbitals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:325503. [PMID: 34044372 DOI: 10.1088/1361-648x/ac05e5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/27/2021] [Indexed: 06/12/2023]
Abstract
We present a derivation of the full formula to calculate the Berry curvature on non-orthogonal numerical atomic orbital (NAO) bases. Because usually, the number of NAOs is larger than that of the Wannier bases, we use a orbital contraction method to reduce the basis sizes, which can greatly improve the calculation efficiency without significantly reducing the calculation accuracy. We benchmark the formula by calculating the Berry curvature of ferroelectric BaTiO3and bcc Fe, as well as the anomalous Hall conductivity for Fe. The results are in excellent agreement with the finite-difference and previous results in the literature. We find that there are corrections terms to the Kubo formula of the Berry curvature. For the full NAO base, the differences between the two methods are negligibly small, but for the reduced bases sets, the correction terms become larger, which may not be neglected in some cases. The formula developed in this work can readily be applied to the non-orthogonal generalized Wannier functions.
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Affiliation(s)
- Gan Jin
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, People's Republic of China
| | - Daye Zheng
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, People's Republic of China
| | - Lixin He
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, People's Republic of China
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9
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Xie K, Li X, Cao T. Theory and Ab Initio Calculation of Optically Excited States-Recent Advances in 2D Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e1904306. [PMID: 31808581 DOI: 10.1002/adma.201904306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/19/2019] [Indexed: 05/16/2023]
Abstract
Recent studies of the optical properties of 2D materials have reported unique phenomena and features that are absent in conventional bulk semiconductors. Many of these interesting properties, such as enhanced light-matter coupling, gate-tunable photoluminescence, and unusual excitonic optical selection rules arise from the nature of the two- and multi-particle excited states such as strongly bound Wannier excitons and charged excitons. The theory, modeling, and ab initio calculations of these optically excited states in 2D materials are reviewed. Several analytical and ab initio approaches are introduced. These methods are compared with each other, revealing their relative strength and limitations. Recent works that apply these methods to a variety of 2D materials and material-defect systems are then highlighted. Understanding of the optically excited states in these systems is relevant not only for fundamental scientific research of electronic excitations and correlations, but also plays an important role in the future development of quantum information science and nano-photonics.
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Affiliation(s)
- Kaichen Xie
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
| | - Xiaosong Li
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
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10
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Kim Y, Hu Z, Avdeev ID, Singh A, Singh A, Chandrasekaran V, Nestoklon MO, Goupalov SV, Hollingsworth JA, Htoon H. Interplay of Bright Triplet and Dark Excitons Revealed by Magneto-Photoluminescence of Individual PbS/CdS Quantum Dots. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006977. [PMID: 33690965 DOI: 10.1002/smll.202006977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/22/2021] [Indexed: 06/12/2023]
Abstract
A low-temperature polarization-resolved magneto-photoluminescence experiment is performed on individual PbS/CdS core/shell quantum dots (QDs). The experiment enables a direct measurement of the exciton Landé g factor and the anisotropic zero-field splitting of the lowest emissive bright exciton triplet in PbS/CdS QDs. While anisotropic splittings of individual QDs distribute randomly in 104-325 μeV range, the exciton Landé g factors increase from 0.95 to 2.70 as the emission energy of the QD increases from 1.0 to 1.2 eV. The tight-binding calculations allow to rationalize these trends as a direct consequence of reducing a cubic symmetry of QD via addition/removal of a few (<70) atoms from the surfaces of the PbS core. Furthermore, it is observed that while right (σ + ) and left (σ - ) circularly polarized photoluminescence (PL) peaks split linearly with magnetic field as expected for Zeeman effect, the energy splitting between X and Y linearly polarized PL peaks remains nearly unchanged. The theoretical study reveals rich and complex magnetic field-induced interplay of bright triplet and dark exciton states explaining this puzzling behavior. These findings fill the missing gaps in the understanding of lead salt QDs and provide foundation for development of classical and quantum light sources operating at telecommunication wavelengths.
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Affiliation(s)
- Younghee Kim
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Zhongjian Hu
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | - Ajay Singh
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Amita Singh
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Vigneshwaran Chandrasekaran
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | - Serguei V Goupalov
- Ioffe Institute, St. Petersburg, 194021, Russia
- Department of Physics, Jackson State University, Jackson, MS 39217, USA
| | - Jennifer A Hollingsworth
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Han Htoon
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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11
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Zhou Y, Liu F. Realization of an Antiferromagnetic Superatomic Graphene: Dirac Mott Insulator and Circular Dichroism Hall Effect. NANO LETTERS 2021; 21:230-235. [PMID: 33263394 DOI: 10.1021/acs.nanolett.0c03579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Using first-principles calculations, we investigate the electronic and topological properties of an antiferromagnetic (AFM) superatomic graphene lattice superimposed on a bipartite honeycomb lattice governed by Lieb's theorem of itinerant magnetism. It affords a concrete material realization of the AFM honeycomb model with a Dirac Mott insulating state, characterized by a gap opening at the Dirac point due to inversion symmetry breaking by long-range AFM order. The opposite Berry curvatures of the K and K' valleys induces a circular dichroism (CD) Hall effect. Different from the valley Hall effect that activates only one valley, the CD Hall effect activates carriers from both K and K' valleys, generating the opposite directions of transversal Hall currents for the left- and right-handed circularly polarized light, respectively.
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Affiliation(s)
- Yinong Zhou
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, United States
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12
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Electron g-factor in nanostructures: continuum media and atomistic approach. Sci Rep 2020; 10:22001. [PMID: 33319860 PMCID: PMC7738673 DOI: 10.1038/s41598-020-79133-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/04/2020] [Indexed: 11/08/2022] Open
Abstract
We report studies of [Formula: see text]-dependent Landé g-factor, performed by both continuous media approximation [Formula: see text] method, and atomistic tight-binding [Formula: see text] approach. We propose an effective, mesoscopic model for InAs that we are able to successfully compare with atomistic calculations, for both very small and very large nanostructures, with a number of atoms reaching over 60 million. Finally, for nanostructure dimensions corresponding to near-zero g-factor we report electron spin states anti-crossing as a function of system size, despite no shape-anisotropy nor strain effects included, and merely due to breaking of atomistic symmetry of cation/anion planes constituting the system.
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13
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Nestoklon MO, Avdeev ID, Belolipetskiy AV, Sychugov I, Pevere F, Linnros J, Yassievich IN. Tight-binding calculations of the optical properties of Si nanocrystals in a SiO 2 matrix. Faraday Discuss 2020; 222:258-273. [PMID: 32100764 DOI: 10.1039/c9fd00090a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We develop an empirical tight binding approach for the modeling of the electronic states and optical properties of Si nanocrystals embedded in a SiO2 matrix. To simulate the wide band gap SiO2 matrix we use the virtual crystal approximation. The tight-binding parameters of the material with the diamond crystal lattice are fitted to the band structure of β-cristobalite. This model of the SiO2 matrix allows us to reproduce the band structure of real Si nanocrystals embedded in a SiO2 matrix. In this model, we compute the absorption spectra of the system. The calculations are in an excellent agreement with experimental data. We find that an important part of the high-energy absorption is defined by the spatially indirect, but direct in k-space transitions between holes inside the nanocrystal and electrons in the matrix.
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14
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Pizzi G, Vitale V, Arita R, Blügel S, Freimuth F, Géranton G, Gibertini M, Gresch D, Johnson C, Koretsune T, Ibañez-Azpiroz J, Lee H, Lihm JM, Marchand D, Marrazzo A, Mokrousov Y, Mustafa JI, Nohara Y, Nomura Y, Paulatto L, Poncé S, Ponweiser T, Qiao J, Thöle F, Tsirkin SS, Wierzbowska M, Marzari N, Vanderbilt D, Souza I, Mostofi AA, Yates JR. Wannier90 as a community code: new features and applications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:165902. [PMID: 31658458 DOI: 10.1088/1361-648x/ab51ff] [Citation(s) in RCA: 247] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Wannier90 is an open-source computer program for calculating maximally-localised Wannier functions (MLWFs) from a set of Bloch states. It is interfaced to many widely used electronic-structure codes thanks to its independence from the basis sets representing these Bloch states. In the past few years the development of Wannier90 has transitioned to a community-driven model; this has resulted in a number of new developments that have been recently released in Wannier90 v3.0. In this article we describe these new functionalities, that include the implementation of new features for wannierisation and disentanglement (symmetry-adapted Wannier functions, selectively-localised Wannier functions, selected columns of the density matrix) and the ability to calculate new properties (shift currents and Berry-curvature dipole, and a new interface to many-body perturbation theory); performance improvements, including parallelisation of the core code; enhancements in functionality (support for spinor-valued Wannier functions, more accurate methods to interpolate quantities in the Brillouin zone); improved usability (improved plotting routines, integration with high-throughput automation frameworks), as well as the implementation of modern software engineering practices (unit testing, continuous integration, and automatic source-code documentation). These new features, capabilities, and code development model aim to further sustain and expand the community uptake and range of applicability, that nowadays spans complex and accurate dielectric, electronic, magnetic, optical, topological and transport properties of materials.
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Affiliation(s)
- Giovanni Pizzi
- Theory and Simulation of Materials (THEOS) and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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15
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Hu Z, Kim Y, Krishnamurthy S, Avdeev ID, Nestoklon MO, Singh A, Malko AV, Goupalov SV, Hollingsworth JA, Htoon H. Intrinsic Exciton Photophysics of PbS Quantum Dots Revealed by Low-Temperature Single Nanocrystal Spectroscopy. NANO LETTERS 2019; 19:8519-8525. [PMID: 31714793 DOI: 10.1021/acs.nanolett.9b02937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
With a tunable size-dependent photoluminescence (PL) over a wide infrared wavelength range, lead chalcogenide quantum dots (QDs) have attracted significant scientific and technological interest. Nevertheless, the investigation of intrinsic exciton photophysics at the single-QD level has remained a challenge. Herein, we present a comprehensive study of PL properties for the individual core/shell PbS/CdS QDs emissive near 1.0 eV. In contrast to the sub-meV spectral line widths observed for II/VI QDs, PbS/CdS QDs are predicted to possess broad homogeneous line widths. Performing spectroscopy at cryogenic (4 K) temperatures, we provide direct evidence confirming theoretical predictions, showing that intrinsic line widths for PbS/CdS QDs are in the range of 8-25 meV, with an average of 16.4 meV. In addition, low-temperature, single-QD spectroscopy reveals a broad low-energy side emission attributable to optical as well as localized acoustic phonon-assisted transitions. By tracking single QDs from 4 to 250 K, we were able to probe temperature-dependent evolutions of emission energy, line width, and line shape. Finally, polarization-resolved PL imaging showed that PbS/CdS QDs are characterized by a 3D emission dipole, in contrast with the 2D dipole observed for CdSe QDs.
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Affiliation(s)
- Zhongjian Hu
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Younghee Kim
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Sachidananda Krishnamurthy
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | | | | | - Ajay Singh
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Anton V Malko
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Serguei V Goupalov
- Ioffe Institute , 194021 St. Petersburg , Russia
- Department of Physics , Jackson State University , Jackson , Mississippi 39217 , United States
| | - Jennifer A Hollingsworth
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Han Htoon
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
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16
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Lü XL, Zhang CX, Wang WJ, Cheng X, Xie H. Excitation and phase transitions of spin density waves in graphene nanoribbons. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:455501. [PMID: 31315099 DOI: 10.1088/1361-648x/ab32ff] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Anti-ferromagnetic states widely exist on graphene zigzag edges. Our previous work (Xie et al 2018 New J. Phys. 20 013035) shows there are also various spin density wave (SDW) states in the graphene nanoribbons (GNR). In this paper, we propose some excitation mechanism of these SDW by the absorbed magnetic atoms with the mean-field Hubbard model and the first-principles calculations. With the Floquet theory, we also find that by regulating the temperature or the light intensity, there are a lot of phase transitions for these SDW. The temperature or light can dramatically modify the inter-edge coupling or the spin stiffness of GNR. The artificial magnetization technique is employed to explore the establishment process of these SDW states. Some interesting intermedia phase transitions and the corresponding spin orders are discovered. This research may be helpful in the understandings and technique controls of magnetic orders in future nano magnetic devices.
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Affiliation(s)
- Xiao-Long Lü
- Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China
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17
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Abstract
Graphene, despite its centrosymmetric structure, is predicted to have a substantial second order nonlinearity, arising from non-local effects. However, there is disagreement between several published theories and experimental data. Here we derive an expression for the second order conductivity of graphene in the non-local regime using perturbation theory, concentrating on the difference frequency mixing process, and compare our results with those already published. We find a second-order conductivity (σ(2) ≈ 10−17 AmV−2) that is approximately three orders of magnitude less than that estimated from recent experimental results. This indicates that nonlinear optical coupling to plasmons in graphene cannot be described perturbatively through the electronic nonlinearity, as previously thought. We also show that this discrepancy cannot be attributed to the bulk optical nonlinearity of the substrate. As a possible alternative, we present a simple theoretical model of how a non-linearity can arise from photothermal effects, which generates a field at least two orders of magnitude larger than that found from perturbation theory.
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18
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Bravo S, Correa J, Chico L, Pacheco M. Tight-binding model for opto-electronic properties of penta-graphene nanostructures. Sci Rep 2018; 8:11070. [PMID: 30038379 PMCID: PMC6056545 DOI: 10.1038/s41598-018-29288-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 07/03/2018] [Indexed: 01/17/2023] Open
Abstract
We present a tight-binding parametrization for penta-graphene that correctly describes its electronic band structure and linear optical response. The set of parameters is validated by comparing to ab-initio density functional theory calculations for single-layer penta-graphene, showing a very good global agreement. We apply this parameterization to penta-graphene nanoribbons, achieving an adequate description of quantum-size effects. Additionally, a symmetry-based analysis of the energy band structure and the optical transitions involved in the absorption spectra is introduced, allowing for the interpretation of the optoelectronic features of these systems.
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Affiliation(s)
- Sergio Bravo
- Universidad Técnica Federico Santa María, Departamento de Física, Valparaíso, Casilla, 110-V, Chile
| | - Julián Correa
- Universidad de Medellín, Facultad de Ciencias Básicas, Medellín, Colombia
| | - Leonor Chico
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), C/ Sor Juana Inés de la Cruz 3, 28049, Madrid, Spain
| | - Mónica Pacheco
- Universidad Técnica Federico Santa María, Departamento de Física, Valparaíso, Casilla, 110-V, Chile.
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19
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Mlinar V. Effects of a magnetic field on the optoelectronic properties of mono- and bi-layer transition metal dichalcogenides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:275502. [PMID: 29848805 DOI: 10.1088/1361-648x/aac908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report a theoretical study on the effects of an external magnetic field on the electronic and optical properties of mono- and bi-layer MoS2, and bilayer MoS2/WS2 heterostructures. The direction of an applied magnetic field determines (i) the strength of the coupling between the atomic orbital moments of the structure and the field, and (ii) Zeeman contribution to the splitting of the VB and CB levels with the amplitude of the applied field. Whereas for a magnetic field applied perpendicular to the structure, calculated real part of optical conductivity reveals optical transitions red-shifted compared to zero magnetic field case, conductivity is unaffected by the the amplitude of an in-plane applied magnetic field. We show that through modifying atomic d-orbitals conduction and valence band states by an applied electric field, we can determine and control the impact of a magnetic field on the optical response of these materials. We employ our parametrized tight-binding model with non-orthogonal sp3d5 orbitals and spin-orbit coupling, which was advanced to include the effects of an external magnetic field through Peierls substitution in the wave vector and the Zeeman energy term.
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Affiliation(s)
- Vladan Mlinar
- Research Institute for Advanced Materials Design, Providence, RI 02906, United States of America
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20
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Spoor FM, Grimaldi G, Delerue C, Evers WH, Crisp RW, Geiregat P, Hens Z, Houtepen AJ, Siebbeles LDA. Asymmetric Optical Transitions Determine the Onset of Carrier Multiplication in Lead Chalcogenide Quantum Confined and Bulk Crystals. ACS NANO 2018; 12:4796-4802. [PMID: 29664600 PMCID: PMC5968429 DOI: 10.1021/acsnano.8b01530] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/17/2018] [Indexed: 05/27/2023]
Abstract
Carrier multiplication is a process in which one absorbed photon excites two or more electrons. This is of great promise to increase the efficiency of photovoltaic devices. Until now, the factors that determine the onset energy of carrier multiplication have not been convincingly explained. We show experimentally that the onset of carrier multiplication in lead chalcogenide quantum confined and bulk crystals is due to asymmetric optical transitions. In such transitions most of the photon energy in excess of the band gap is given to either the hole or the electron. The results are confirmed and explained by theoretical tight-binding calculations of the competition between impact ionization and carrier cooling. These results are a large step forward in understanding carrier multiplication and allow for a screening of materials with an onset of carrier multiplication close to twice the band gap energy. Such materials are of great interest for development of highly efficient photovoltaic devices.
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Affiliation(s)
- Frank
C. M. Spoor
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Gianluca Grimaldi
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | | | - Wiel H. Evers
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Ryan W. Crisp
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Pieter Geiregat
- Physics
and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Zeger Hens
- Physics
and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Arjan J. Houtepen
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Laurens D. A. Siebbeles
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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21
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Pötz W. Single-cone finite-difference schemes for the (2+1)-dimensional Dirac equation in general electromagnetic textures. Phys Rev E 2018; 96:053312. [PMID: 29347729 DOI: 10.1103/physreve.96.053312] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Indexed: 11/07/2022]
Abstract
A single-cone finite-difference lattice scheme is developed for the (2+1)-dimensional Dirac equation in presence of general electromagnetic textures. The latter is represented on a (2+1)-dimensional staggered grid using a second-order-accurate finite difference scheme. A Peierls-Schwinger substitution to the wave function is used to introduce the electromagnetic (vector) potential into the Dirac equation. Thereby, the single-cone energy dispersion and gauge invariance are carried over from the continuum to the lattice formulation. Conservation laws and stability properties of the formal scheme are identified by comparison with the scheme for zero vector potential. The placement of magnetization terms is inferred from consistency with the one for the vector potential. Based on this formal scheme, several numerical schemes are proposed and tested. Elementary examples for single-fermion transport in the presence of in-plane magnetization are given, using material parameters typical for topological insulator surfaces.
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Affiliation(s)
- Walter Pötz
- Institut für Physik, Karl-Franzens-Universität Graz, Universitätsplatz 5, 8010 Graz, Austria
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22
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Ji H, Dhomkar S, Wu R, Ludwig J, Lu Z, Smirnov D, Tamargo MC, Bryant GW, Kuskovsky IL. Long spin-flip time and large Zeeman splitting of holes in type-II ZnTe/ZnSe submonolayer quantum dots. JOURNAL OF APPLIED PHYSICS 2018; 124:10.1063/1.5041478. [PMID: 31274882 PMCID: PMC6604638 DOI: 10.1063/1.5041478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/22/2018] [Indexed: 06/09/2023]
Abstract
The Zeeman splitting and degree of circular polarization (DCP) of photoluminescence (PL) from type-II submonolayer ZnTe/ZnSe quantum dots (QDs) have been investigated in magnetic fields up to 18 T. To explain the observed relative intensities and energy positions of the σ+ and the σ- PL, a non-Boltzmann distribution for holes with ultra-long spin-flip time, confined to submonolayer QDs, is proposed. The g-factor of electrons, located in the ZnSe barriers, was obtained from fitting the temperature dependence of the DCP, and its value is in excellent agreement with that of bulk ZnSe. The g-factor of type-II excitons was extracted by analyzing the Zeeman splitting, from which the g-factor of holes confined within submonolayer ZnTe QDs was found to be ~2.65 ± 0.40. This value is considerably larger than that in bulk ZnTe. Tight-binding calculations using an sp 3 s* model were employed to understand the origin of such an increase. The results of the simulation match the experiment and show that the enhancement of the hole g-factor is mostly caused by a reduced orbital contribution to Zeeman splitting arising from the submonolayer thickness of these QDs.
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Affiliation(s)
- H. Ji
- Department of Physics, Queens College of CUNY, Queens, New York 11367, USA
- The Graduate Center of CUNY, New York, New York 10016, USA
| | - S. Dhomkar
- Department of Physics, Queens College of CUNY, Queens, New York 11367, USA
- The Graduate Center of CUNY, New York, New York 10016, USA
| | - R. Wu
- Department of Physics, Queens College of CUNY, Queens, New York 11367, USA
- The Graduate Center of CUNY, New York, New York 10016, USA
| | - J. Ludwig
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - Z. Lu
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - D. Smirnov
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | - M. C. Tamargo
- The Graduate Center of CUNY, New York, New York 10016, USA
- Department of Chemistry, City College of CUNY, New York, New York 10031, USA
| | - G. W. Bryant
- Quantum Measurement Division and Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423, USA
| | - I. L. Kuskovsky
- Department of Physics, Queens College of CUNY, Queens, New York 11367, USA
- The Graduate Center of CUNY, New York, New York 10016, USA
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23
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Abstract
The realization of high-performance, small-footprint, on-chip inductors remains a challenge in radio-frequency and power microelectronics, where they perform vital energy transduction in filters and power converters. Modern planar inductors consist of metallic spirals that consume significant chip area, resulting in low inductance densities. We present a novel method for magnetic energy transduction that utilizes ferromagnetic islands (FIs) on the surface of a 3D time-reversal-invariant topological insulator (TI) to produce paradigmatically different inductors. Depending on the chemical potential, the FIs induce either an anomalous or quantum anomalous Hall effect in the topological surface states. These Hall effects direct current around the FIs, concentrating magnetic flux and producing a highly inductive device. Using a novel self-consistent simulation that couples AC non-equilibrium Green functions to fully electrodynamic solutions of Maxwell's equations, we demonstrate excellent inductance densities up to terahertz frequencies, thus harnessing the unique properties of topological materials for practical device applications.
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24
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Winkler GW, Varjas D, Skolasinski R, Soluyanov AA, Troyer M, Wimmer M. Orbital Contributions to the Electron g Factor in Semiconductor Nanowires. PHYSICAL REVIEW LETTERS 2017; 119:037701. [PMID: 28777644 DOI: 10.1103/physrevlett.119.037701] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Indexed: 06/07/2023]
Abstract
Recent experiments on Majorana fermions in semiconductor nanowires [S. M. Albrecht, A. P. Higginbotham, M. Madsen, F. Kuemmeth, T. S. Jespersen, J. Nygård, P. Krogstrup, and C. M. Marcus, Nature (London) 531, 206 (2016)NATUAS0028-083610.1038/nature17162] revealed a surprisingly large electronic Landé g factor, several times larger than the bulk value-contrary to the expectation that confinement reduces the g factor. Here we assess the role of orbital contributions to the electron g factor in nanowires and quantum dots. We show that an L·S coupling in higher subbands leads to an enhancement of the g factor of an order of magnitude or more for small effective mass semiconductors. We validate our theoretical finding with simulations of InAs and InSb, showing that the effect persists even if cylindrical symmetry is broken. A huge anisotropy of the enhanced g factors under magnetic field rotation allows for a straightforward experimental test of this theory.
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Affiliation(s)
- Georg W Winkler
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
| | - Dániel Varjas
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Rafal Skolasinski
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
| | - Alexey A Soluyanov
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
- Department of Physics, Saint Petersburg State University, Saint Petersburg 199034, Russia
| | - Matthias Troyer
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
- Quantum Architectures and Computation Group, Microsoft Research, Redmond, Washington 98052, USA
| | - Michael Wimmer
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, Netherlands
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25
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Winkler GW, Wu Q, Troyer M, Krogstrup P, Soluyanov AA. Topological Phases in InAs_{1-x}Sb_{x}: From Novel Topological Semimetal to Majorana Wire. PHYSICAL REVIEW LETTERS 2016; 117:076403. [PMID: 27563979 DOI: 10.1103/physrevlett.117.076403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Indexed: 06/06/2023]
Abstract
Superconductor proximitized one-dimensional semiconductor nanowires with strong spin-orbit interaction (SOI) are, at this time, the most promising candidates for the realization of topological quantum information processing. In current experiments the SOI originates predominantly from extrinsic fields, induced by finite size effects and applied gate voltages. The dependence of the topological transition in these devices on microscopic details makes scaling to a large number of devices difficult unless a material with dominant intrinsic bulk SOI is used. Here, we show that wires made of certain ordered alloys InAs_{1-x}Sb_{x} have spin splittings up to 20 times larger than those reached in pristine InSb wires. In particular, we show this for a stable ordered CuPt structure at x=0.5, which has an inverted band ordering and realizes a novel type of a topological semimetal with triple degeneracy points in the bulk spectrum that produce topological surface Fermi arcs. Experimentally achievable strains can either drive this compound into a topological insulator phase or restore the normal band ordering, making the CuPt-ordered InAs_{0.5}Sb_{0.5} a semiconductor with a large intrinsic linear in k bulk spin splitting.
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Affiliation(s)
- Georg W Winkler
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
| | - QuanSheng Wu
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
| | - Matthias Troyer
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
| | - Peter Krogstrup
- Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Alexey A Soluyanov
- Theoretical Physics and Station Q Zurich, ETH Zurich, 8093 Zurich, Switzerland
- Department of Physics, St. Petersburg State University, St. Petersburg 199034, Russia
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26
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Ma X, Bryant GW, Doty MF. Hole spins in an InAs/GaAs quantum dot molecule subject to lateral electric fields. PHYSICAL REVIEW. B 2016; 93:10.1103/physrevb.93.245402. [PMID: 32118123 PMCID: PMC7047739 DOI: 10.1103/physrevb.93.245402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There has been tremendous progress in manipulating electron and hole-spin states in quantum dots or quantum dot molecules (QDMs) with growth-direction (vertical) electric fields and optical excitations. However, the response of carriers in QDMs to an in-plane (lateral) electric field remains largely unexplored. We computationally explore spin-mixing interactions in the molecular states of single holes confined in vertically stacked InAs/GaAs QDMs using atomistic tight-binding simulations. We systematically investigate QDMs with different geometric structure parameters and local piezoelectric fields. We observe both a relatively large Stark shift and a change in the Zeeman splitting as the magnitude of the lateral electric field increases. Most importantly, we observe that lateral electric fields induce hole-spin mixing with a magnitude that increases with increasing lateral electric field over a moderate range. These results suggest that applied lateral electric fields could be used to fine tune and manipulate, in situ, the energy levels and spin properties of single holes confined in QDMs.
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Affiliation(s)
- Xiangyu Ma
- Dept. of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - Garnett W. Bryant
- Quantum Measurement Division and Joint Quantum Institute, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8423, Gaithersburg, Maryland 20899-8423, USA
| | - Matthew F. Doty
- Dept. of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
- Dept. of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, USA
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27
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Inoue JI. Adiabatic photo-steering theory in topological insulators. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2014; 15:064403. [PMID: 27877726 PMCID: PMC5090385 DOI: 10.1088/1468-6996/15/6/064403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/09/2014] [Accepted: 11/16/2014] [Indexed: 06/06/2023]
Abstract
Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane-Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed.
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Affiliation(s)
- Jun-ichi Inoue
- National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044 Japan
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28
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Rusin TM, Zawadzki W. Zitterbewegung of electrons in carbon nanotubes created by laser pulses. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:215301. [PMID: 24786978 DOI: 10.1088/0953-8984/26/21/215301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We describe a possibility of creating non-stationary electron wave packets in zigzag carbon nanotubes (CNT) illuminated by short laser pulses. After the disappearance of the pulse the packet experiences a trembling motion (Zitterbewegung, ZB). The band structure of CNT is calculated using the tight-binding approximation generalized for the presence of radiation. By employing realistic pulse and CNT parameters we obtain the ZB oscillations with interband frequencies corresponding to specific pairs of energy bands. A choice of optimal parameters is presented in order to observe the phenomenon of ZB experimentally. The use of Gaussian wave packets to trigger the electron Zitterbewegung, as used in the literature, is critically reexamined.
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Affiliation(s)
- T M Rusin
- Orange Customer Service sp. z o. o., Al. Jerozolimskie, 02-326 Warsaw, Poland
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Yuan S, Shen Z, Zhang W, Dou Y, Lo GV. Thymine dimer splitting in the T<>T-G trinucleotide model system: a semiclassical dynamics and TD-DFT study. Int J Biol Macromol 2014; 66:267-72. [PMID: 24589472 DOI: 10.1016/j.ijbiomac.2014.02.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/18/2014] [Accepted: 02/21/2014] [Indexed: 10/25/2022]
Abstract
The mechanism leading to bond cleavage of a thymine-thymine cyclobutane dimer (T<>T) in a model system consisting of the dimer flanked by guanine trinucleotide was studied using semiclassical dynamics simulation. Pulsed laser excitation of the guanine molecule is found to cause electron transfer from the guanine molecule to the dimer, which then dissociates via sequential cleavage of the C5C5' and C6C6' bonds. Subsequently, electrons transfer back to the guanine molecule as the dimer splits into two monomers. The splitting of the cyclobutane dimer was found to be in the femtosecond time scale.
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Affiliation(s)
- Shuai Yuan
- Institute of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, PR China
| | - Zhi Shen
- Institute of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, PR China
| | - Wenying Zhang
- Institute of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, PR China
| | - Yusheng Dou
- Institute of Bioinformatics, Chongqing University of Posts and Telecommunications, Chongqing, 400065, PR China; Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, LA 70310, USA.
| | - Glenn V Lo
- Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, LA 70310, USA
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Esfahani DN, Covaci L, Peeters FM. Surface correlation effects in two-band strongly correlated slabs. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:075601. [PMID: 24627895 DOI: 10.1088/0953-8984/26/7/075601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Using an extension of the Gutzwiller approximation for an inhomogeneous system, we study the two-band Hubbard model with unequal band widths for a slab geometry. The aim is to investigate the mutual effect of individual bands on the spatial distribution of quasi-particle weight and charge density, especially near the surface of the slab. The main effect of the difference in band width is the presence of two different length scales corresponding to the quasi-particle profile of each band. This is enhanced in the vicinity of the critical interaction of the narrow band where an orbitally selective Mott transition occurs and a surface dead layer forms for the narrow band. For the doped case, two different regimes of charge transfer between the surface and the bulk of the slab are revealed. The charge transfer from surface/center to center/surface depends on both the doping level and the average relative charge accumulated in each band. Such effects could also be of importance when describing the accumulation of charges at the interface between structures made of multi-band strongly correlated materials.
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Long Z, Zhou X, Cai H, Chen C, Miao L, Allen RE. Breathing-trap mechanism for encapsulation of atomic hydrogen in C60. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.07.070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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32
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Dou Y, Liu Z, Yuan S, Zhang W, Tang H, Zhao J, Fang W, Lo GV. Dynamics of laser-excited stacked adenines: Semiclassical simulations. Int J Biol Macromol 2013; 52:358-67. [DOI: 10.1016/j.ijbiomac.2012.10.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/01/2012] [Accepted: 10/06/2012] [Indexed: 11/16/2022]
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Molina-Sánchez A, García-Cristóbal A. Anisotropic optical response of GaN and AlN nanowires. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:295301. [PMID: 22739320 DOI: 10.1088/0953-8984/24/29/295301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a theoretical study of the electronic structure and optical properties of free-standing GaN and AlN nanowires. We have implemented the empirical tight-binding method, with an orbital basis sp(3), that includes the spin-orbit interaction. The passivation of the dangling bonds at the free surfaces is also studied, together with the effects on the electronic structure of the nanowire. For both GaN and AlN nanowires, we have found a remarkable anisotropy of the optical absorption when the light-polarization changes, showing in the case of GaN a dependence on the nanowire size.
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Affiliation(s)
- A Molina-Sánchez
- Instituto de Ciencia de Materiales, Universidad de Valencia, E-46071 Valencia, Spain.
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34
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Akande A, Sanvito S. Persistent current and Drude weight for the one-dimensional Hubbard model from current lattice density functional theory. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:055602. [PMID: 22248571 DOI: 10.1088/0953-8984/24/5/055602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Bethe ansatz local density approximation (LDA) to lattice density functional theory (LDFT) for the one-dimensional repulsive Hubbard model is extended to current-LDFT (CLDFT). The transport properties of mesoscopic Hubbard rings threaded by a magnetic flux are then systematically investigated by this scheme. In particular we present calculations of ground state energies, persistent currents and Drude weights for both a repulsive homogeneous and a single impurity Hubbard model. Our results for the ground state energies in the metallic phase compare favorably well with those obtained with numerically accurate many-body techniques. Also the dependence of the persistent currents on the Coulomb and the impurity interaction strength, and on the ring size are all well captured by LDA-CLDFT. Our study demonstrates the value of CLDFT in describing the transport properties of one-dimensional correlated electron systems. As its computational overheads are rather modest, we propose this method as a tool for studying problems where both disorder and interaction are present.
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Affiliation(s)
- A Akande
- School of Physics and CRANN, Trinity College, Dublin 2, Ireland.
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Verdozzi C, Karlsson D, Puig von Friesen M, Almbladh CO, von Barth U. Some open questions in TDDFT: Clues from lattice models and Kadanoff–Baym dynamics. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2011.04.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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36
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Yuan S, Zhang W, Liu L, Dou Y, Fang W, Lo GV. Detailed mechanism for photoinduced cytosine dimerization: a semiclassical dynamics simulation. J Phys Chem A 2011; 115:13291-7. [PMID: 21988470 DOI: 10.1021/jp207550a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Semiclassical dynamics simulation is used to study dimerization of two stacked cytosine molecules following excitation by ultrashort laser pulses (25 fs fwhm, Gaussian, 4.1 eV photon energy). The initial excited state was found to form an ultrashort exciton state, which eventually leads to the formation of an excimer state by charge transfer. When the interbase distance, defined as an average value of C(5)-C(5)' and C(6)-C(6)', becomes less than 3 Å, charge recombination occurs due to strong intermolecular interaction, eventually leading to an avoided crossing within 20-30 fs. Geometries at the avoided crossing, with average intermolecular distance of about 2.1 Å, are in accord with CASSCF/CASPT2 calculations. Results indicate that the C(2)-N(1)-C(6)-C(5) and C(2)'-N(1)'-C(6)'-C(5)' dihedral angles' bending vibrations play a significant role in the vibronic coupling between the HOMO and LUMO, which leads to a nonadiabatic transition to the electronic ground state.
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Affiliation(s)
- Shuai Yuan
- Department of Chemistry, Beijing Normal University, Beijing, China
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Usman M, Tan YHM, Ryu H, Ahmed SS, Krenner HJ, Boykin TB, Klimeck G. Quantitative excited state spectroscopy of a single InGaAs quantum dot molecule through multi-million-atom electronic structure calculations. NANOTECHNOLOGY 2011; 22:315709. [PMID: 21737873 DOI: 10.1088/0957-4484/22/31/315709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Atomistic electronic structure calculations are performed to study the coherent inter-dot couplings of the electronic states in a single InGaAs quantum dot molecule. The experimentally observed excitonic spectrum by Krenner et al (2005) Phys. Rev. Lett. 94 057402 is quantitatively reproduced, and the correct energy states are identified based on a previously validated atomistic tight binding model. The extended devices are represented explicitly in space with 15-million-atom structures. An excited state spectroscopy technique is applied where the externally applied electric field is swept to probe the ladder of the electronic energy levels (electron or hole) of one quantum dot through anti-crossings with the energy levels of the other quantum dot in a two-quantum-dot molecule. This technique can be used to estimate the spatial electron-hole spacing inside the quantum dot molecule as well as to reverse engineer quantum dot geometry parameters such as the quantum dot separation. Crystal-deformation-induced piezoelectric effects have been discussed in the literature as minor perturbations lifting degeneracies of the electron excited (P and D) states, thus affecting polarization alignment of wavefunction lobes for III-V heterostructures such as single InAs/GaAs quantum dots. In contrast, this work demonstrates the crucial importance of piezoelectricity to resolve the symmetries and energies of the excited states through matching the experimentally measured spectrum in an InGaAs quantum dot molecule under the influence of an electric field. Both linear and quadratic piezoelectric effects are studied for the first time for a quantum dot molecule and demonstrated to be indeed important. The net piezoelectric contribution is found to be critical in determining the correct energy spectrum, which is in contrast to recent studies reporting vanishing net piezoelectric contributions.
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Affiliation(s)
- Muhammad Usman
- School of Electrical and Computer Engineering and Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47906, USA.
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Zhang W, Yuan S, Wang Z, Qi Z, Zhao J, Dou Y, Lo GV. A semiclassical dynamics simulation for a long-lived excimer state of π-stacked adenines. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.03.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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39
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Tang H, Li H, Dou Y. Laser induced C(60) cage opening studied by semiclassical dynamics simulation. Int J Mol Sci 2011; 12:353-61. [PMID: 21339990 PMCID: PMC3039956 DOI: 10.3390/ijms12010353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 10/22/2010] [Accepted: 11/09/2010] [Indexed: 11/17/2022] Open
Abstract
Laser induced opening of the C(60) cage is studied by a semiclassical electron-radiation-ion dynamics technique. The simulation results indicate that the C(60) cage is abruptly opened immediately after laser excitation. The opening of the C(60) cage induces a quick increase in kinetic energy and a sharp decrease in electronic energy, suggesting that the breaking of the C(60) cage efficiently heats up the cluster and enhances the thermal fragmentation of C(60) fullerene.
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Affiliation(s)
- Hong Tang
- Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China; E-Mails: (H.T.); (H.L.)
| | - Hongjian Li
- Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China; E-Mails: (H.T.); (H.L.)
| | - Yusheng Dou
- Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China; E-Mails: (H.T.); (H.L.)
- Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, LA 70310, USA
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Yuan S, Wu W, Wei Z, Shu K, Tang H, Dou Y, Lo GV. A semiclassical dynamics study of the photoisomerization of methyl-substituted azobenzene. Mol Phys 2010. [DOI: 10.1080/00268976.2010.520755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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41
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Tang H, Li H, Dou Y, Fang W. Cage opening and fragmentation of C60fullerene induced by an ultrashort laser pulse. MOLECULAR SIMULATION 2010. [DOI: 10.1080/08927022.2010.498827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Jiang CW, Xie RH, Li FL, Allen RE. Photocyclization of trans-stilbene induced by an ultrafast laser pulse. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.01.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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43
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Lin Z, Allen RE. Ultrafast equilibration of excited electrons in dynamical simulations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:485503. [PMID: 21832522 DOI: 10.1088/0953-8984/21/48/485503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In our density-functional-based simulations of materials responding to femtosecond-scale laser pulses, we have observed a potentially useful phenomenon: the excited electrons automatically equilibrate to a Fermi-Dirac distribution within ∼100 fs, solely because of their coupling to the nuclear motion, even though the resulting electronic temperature is one to two orders of magnitude higher than the kinetic temperature defined by the nuclear motion. Microscopic simulations like these can then provide the separate electronic and kinetic temperatures, chemical potentials, pressures, and nonhydrostatic stresses as input for studies on larger lengths and timescales.
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44
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Li H, Tang H, Dou Y. Laser-induced nonthermal fragmentation of C60studied by semiclassical dynamics simulation. Mol Phys 2009. [DOI: 10.1080/00268970903136621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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45
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Jiang C, Xie R, Li F, Allen RE. Trans-to-cis isomerization of stilbene following an ultrafast laser pulse. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.04.079] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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46
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Dou Y, Hu Y, Yuan S, Wu W, Tang H. Detailed mechanism oftrans–cisphotoisomerization of azobenzene studied by semiclassical dynamics simulation. Mol Phys 2009. [DOI: 10.1080/00268970902769497] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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47
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Yuan S, Dou Y, Wu W, Hu Y, Zhao J. Why Does trans-Azobenzene Have a Smaller Isomerization Yield for ππ* Excitation Than for nπ* Excitation? J Phys Chem A 2008; 112:13326-34. [DOI: 10.1021/jp806227x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Shuai Yuan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico—Inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an, 710069, China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China, and Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux, Louisiana 70310
| | - Yusheng Dou
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico—Inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an, 710069, China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China, and Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux, Louisiana 70310
| | - Weifeng Wu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico—Inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an, 710069, China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China, and Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux, Louisiana 70310
| | - Yun Hu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico—Inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an, 710069, China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China, and Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux, Louisiana 70310
| | - Jianshe Zhao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico—Inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an, 710069, China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China, and Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux, Louisiana 70310
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48
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Dou Y, Wu W, Tang H, Allen RE. Ultrafast laser excitation and rotational de-excitation of cis-stilbene. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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49
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Lei Y, Yuan S, Dou Y, Wang Y, Wen Z. Detailed Dynamics of the Nonradiative Deactivation of Adenine: A Semiclassical Dynamics Study. J Phys Chem A 2008; 112:8497-504. [DOI: 10.1021/jp802483b] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yibo Lei
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, 710069, P. R. China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, P. R. China, and, Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, Louisiana 70310
| | - Shuai Yuan
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, 710069, P. R. China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, P. R. China, and, Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, Louisiana 70310
| | - Yusheng Dou
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, 710069, P. R. China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, P. R. China, and, Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, Louisiana 70310
| | - Yubin Wang
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, 710069, P. R. China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, P. R. China, and, Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, Louisiana 70310
| | - Zhenyi Wen
- Institute of Modern Physics, Northwest University, Xi’an, Shaanxi, 710069, P. R. China, Institute of Computational Chemistry, Chongqing University of Posts and Telecommunications, Chongqing, 400065, P. R. China, and, Department of Physical Sciences, Nicholls State University, PO Box 2022, Thibodaux, Louisiana 70310
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50
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Zhang DB, Hua M, Dumitrică T. Stability of polycrystalline and wurtzite Si nanowires via symmetry-adapted tight-binding objective molecular dynamics. J Chem Phys 2008; 128:084104. [DOI: 10.1063/1.2837826] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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