1
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Kundu A, Galli G. Quantum Vibronic Effects on the Excitation Energies of the Nitrogen-Vacancy Center in Diamond. J Phys Chem Lett 2024; 15:802-810. [PMID: 38232151 DOI: 10.1021/acs.jpclett.3c03269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
We investigated the impact of quantum vibronic coupling on the electronic properties of solid-state spin defects using stochastic methods and first-principles molecular dynamics with a quantum thermostat. Focusing on the negatively charged nitrogen-vacancy center in diamond as an exemplary case, we found a significant dynamic Jahn-Teller splitting of the doubly degenerate single-particle levels within the diamond's band gap, even at 0 K, with a magnitude exceeding 180 meV. This pronounced splitting leads to substantial renormalizations of these levels and, subsequently, of the vertical excitation energies of the doubly degenerate singlet and triplet excited states. Our findings underscore the pressing need to incorporate quantum vibronic effects into first-principles calculations, particularly when comparing computed vertical excitation energies with experimental data. Our study also reveals the efficiency of stochastic thermal line sampling for studying phonon renormalizations of solid-state spin defects.
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Affiliation(s)
- Arpan Kundu
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Giulia Galli
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
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2
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Yang H, Govoni M, Kundu A, Galli G. Combined First-Principles Calculations of Electron-Electron and Electron-Phonon Self-Energies in Condensed Systems. J Chem Theory Comput 2021; 17:7468-7476. [PMID: 34851129 DOI: 10.1021/acs.jctc.1c00605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a method to efficiently combine the computation of electron-electron and electron-phonon self-energies, which enables the evaluation of electron-phonon coupling at the G0W0 level of theory for systems with hundreds of atoms. In addition, our approach, which is a generalization of a method recently proposed for molecules [J. Chem. Theory Comput. 2018, 14, 6269-6275], enables the inclusion of nonadiabatic and temperature effects at no additional computational cost. We present results for diamond and defects in diamond and discuss the importance of numerically accurate G0W0 band structures to obtain robust predictions of zero point renormalization (ZPR) of band gaps, and of the inclusion of nonadiabatic effects to accurately compute the ZPR of defect states in the band gap.
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Affiliation(s)
- Han Yang
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.,Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Marco Govoni
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States.,Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Arpan Kundu
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Giulia Galli
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.,Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States.,Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
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3
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Shang H, Yang J. Capturing the Electron-Phonon Renormalization in Molecules from First-Principles. J Phys Chem A 2021; 125:2682-2689. [PMID: 33755483 DOI: 10.1021/acs.jpca.0c10897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Since the interaction between electrons and atomic nuclei can affect the electronic structure, in recent years, first-principles-based electron-phonon renormalization methods have been applied in the condensed matter physics community to account for the influence of the electron-phonon coupling in solid systems. However, little is yet known about the behavior and trends of the electron-phonon renormalization in the molecules. In this work, the method for the electron-phonon renormalization in molecules has been derived, using which, we exhaustively investigate the zero-point renormalization in 32 molecules with three different density functions. We find that the renormalization of the highest occupied molecular orbital-lowest unoccupied molecular orbital gap due to electron-vibration coupling does not relate to the atomic masses but quite relates to the electronic structure properties of the molecules.
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Affiliation(s)
- Honghui Shang
- State Key Laboratory of Computer Architecture, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinlong Yang
- Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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4
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Gorelov V, Ceperley DM, Holzmann M, Pierleoni C. Electronic structure and optical properties of quantum crystals from first principles calculations in the Born–Oppenheimer approximation. J Chem Phys 2020; 153:234117. [DOI: 10.1063/5.0031843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vitaly Gorelov
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
| | - David M. Ceperley
- Department of Physics, University of Illinois, Urbana, Illinois 61801, USA
| | - Markus Holzmann
- Univ. Grenoble Alpes, CNRS, LPMMC, 3800 Grenoble, France
- Institut Laue Langevin, BP 156, F-38042 Grenoble Cedex 9, France
| | - Carlo Pierleoni
- Maison de la Simulation, CEA, CNRS, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
- Department of Physical and Chemical Sciences, University of L’Aquila, Via Vetoio 10, I-67010 L’Aquila, Italy
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5
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White AF, Gao Y, Minnich AJ, Chan GKL. A coupled cluster framework for electrons and phonons. J Chem Phys 2020; 153:224112. [DOI: 10.1063/5.0033132] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Alec F. White
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Yang Gao
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, USA
| | - Austin J. Minnich
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, USA
| | - Garnet Kin-Lic Chan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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6
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Roy B, Mukhuti K, Bansal B. Experimental determination of the bare energy gap of GaAs without the zero-point renormalization. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:10LT01. [PMID: 31746778 DOI: 10.1088/1361-648x/ab58f8] [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
The energy gap of simple band insulators like GaAs is a strong function of temperature due to the electron-phonon interactions. Interestingly, the perturbation from zero-point phonons is also predicted to cause significant (a few percent) renormalization of the energy gap at absolute zero temperature but its value has been difficult to estimate both theoretically and, of course, experimentally. Given the experimental evidence (Bhattacharya et al 2015 Phys. Rev. Lett. 114 047402) that strongly supports that the exponential broadening (Urbach tail) of the excitonic absorption edge at low temperatures is the manifestation of this zero temperature electron-phonon scattering, we argue that the location of the Urbach focus is the zero temperature unrenormalized gap. Experiments on GaAs yield the zero temperature bare energy gap to be 1.581 eV and thus the renormalization is estimated to be 66 meV.
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Affiliation(s)
- Basabendra Roy
- Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, West Bengal, India
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7
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Ramakrishna K, Vorberger J. Ab initio dielectric response function of diamond and other relevant high pressure phases of carbon. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:095401. [PMID: 31703214 DOI: 10.1088/1361-648x/ab558e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The electronic structure and dielectric properties of the diamond, body centered cubic diamond (bc8), and hexagonal diamond (lonsdaleite) phases of carbon are computed using density functional theory and many-body perturbation theory with the emphasis on the excitonic picture of the solid phases relevant in the regimes of high-pressure physics and warm dense matter. We also discuss the capabilities of reproducing the inelastic x-ray scattering spectra in comparison with the existing models in light of recent x-ray scattering experiments on carbon and carbon bearing materials in the Megabar range.
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Affiliation(s)
- Kushal Ramakrishna
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany. Technische Universität Dresden, 01062 Dresden, Germany
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8
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Wei W, Huang B, Dai Y. Photoexcited charge carrier behaviors in solar energy conversion systems from theoretical simulations. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2019. [DOI: 10.1002/wcms.1441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Wei Wei
- School of Physics, State Key Laboratory of Crystal Materials Shandong University Jinan China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials Shandong University Jinan China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials Shandong University Jinan China
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9
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Sangalli D, Ferretti A, Miranda H, Attaccalite C, Marri I, Cannuccia E, Melo P, Marsili M, Paleari F, Marrazzo A, Prandini G, Bonfà P, Atambo MO, Affinito F, Palummo M, Molina-Sánchez A, Hogan C, Grüning M, Varsano D, Marini A. Many-body perturbation theory calculations using the yambo code. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:325902. [PMID: 30943462 DOI: 10.1088/1361-648x/ab15d0] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
yambo is an open source project aimed at studying excited state properties of condensed matter systems from first principles using many-body methods. As input, yambo requires ground state electronic structure data as computed by density functional theory codes such as Quantum ESPRESSO and Abinit. yambo's capabilities include the calculation of linear response quantities (both independent-particle and including electron-hole interactions), quasi-particle corrections based on the GW formalism, optical absorption, and other spectroscopic quantities. Here we describe recent developments ranging from the inclusion of important but oft-neglected physical effects such as electron-phonon interactions to the implementation of a real-time propagation scheme for simulating linear and non-linear optical properties. Improvements to numerical algorithms and the user interface are outlined. Particular emphasis is given to the new and efficient parallel structure that makes it possible to exploit modern high performance computing architectures. Finally, we demonstrate the possibility to automate workflows by interfacing with the yambopy and AiiDA software tools.
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Affiliation(s)
- D Sangalli
- Istituto di Struttura della Materia-Consiglio Nazionale delle Ricerche (CNR-ISM), Division of Ultrafast Processes in Materials (FLASHit), Via Salaria Km 29.5, CP 10, I-00016 Monterotondo Stazione, Italy. European Theoretical Spectroscopy Facility (ETSF
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10
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Golze D, Dvorak M, Rinke P. The GW Compendium: A Practical Guide to Theoretical Photoemission Spectroscopy. Front Chem 2019; 7:377. [PMID: 31355177 PMCID: PMC6633269 DOI: 10.3389/fchem.2019.00377] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 05/08/2019] [Indexed: 12/22/2022] Open
Abstract
The GW approximation in electronic structure theory has become a widespread tool for predicting electronic excitations in chemical compounds and materials. In the realm of theoretical spectroscopy, the GW method provides access to charged excitations as measured in direct or inverse photoemission spectroscopy. The number of GW calculations in the past two decades has exploded with increased computing power and modern codes. The success of GW can be attributed to many factors: favorable scaling with respect to system size, a formal interpretation for charged excitation energies, the importance of dynamical screening in real systems, and its practical combination with other theories. In this review, we provide an overview of these formal and practical considerations. We expand, in detail, on the choices presented to the scientist performing GW calculations for the first time. We also give an introduction to the many-body theory behind GW, a review of modern applications like molecules and surfaces, and a perspective on methods which go beyond conventional GW calculations. This review addresses chemists, physicists and material scientists with an interest in theoretical spectroscopy. It is intended for newcomers to GW calculations but can also serve as an alternative perspective for experts and an up-to-date source of computational techniques.
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Affiliation(s)
- Dorothea Golze
- Department of Applied Physics, Aalto University, School of Science, Espoo, Finland
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11
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Kosugi T, Matsushita YI. Wannier interpolation of one-particle Green's functions from coupled-cluster singles and doubles (CCSD). J Chem Phys 2019; 150:114104. [PMID: 30902011 DOI: 10.1063/1.5079474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We propose two schemes for interpolation of the one-particle Green's function (GF) calculated within a coupled-cluster singles and doubles (CCSD) method for a periodic system. These schemes use Wannier orbitals for circumventing huge cost for a large number of sampled k points. One of the schemes is the direct interpolation, which obtains the GF straightforwardly by using Fourier transformation. The other is the self-energy-mediated interpolation, which obtains the GF via the Dyson equation. We apply the schemes to a LiH chain and trans-polyacetylene and examine their validity in detail. It is demonstrated that the direct-interpolated GFs suffer from numerical artifacts stemming from slow convergence of CCSD GFs in real space, while the self-energy-mediated interpolation provides more physically appropriate GFs due to the localized nature of CCSD self-energies. Our schemes are also applicable to other correlated methods capable of providing GFs.
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Affiliation(s)
- Taichi Kosugi
- Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
| | - Yu-Ichiro Matsushita
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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12
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McAvoy RL, Govoni M, Galli G. Coupling First-Principles Calculations of Electron-Electron and Electron-Phonon Scattering, and Applications to Carbon-Based Nanostructures. J Chem Theory Comput 2018; 14:6269-6275. [PMID: 30351009 DOI: 10.1021/acs.jctc.8b00728] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report first-principles calculations of electronic gaps, lifetimes, and photoelectron spectra of a series of molecules, performed by efficiently combining the computation of electron-electron and electron-phonon self-energies. The dielectric matrix is represented in terms of dielectric eigenpotentials, utilized for both the calculation of G0 W0 quasi-particle energies and the diagonalization of the dynamical matrix; virtual electronic states are never explicitly computed and all self-energies are evaluated over the full frequency spectrum. Our formulation enables electronic structure calculations at the many-body perturbation theory level, inclusive of electron-phonon coupling, for systems with hundreds of electrons.
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Affiliation(s)
- Ryan L McAvoy
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States
| | - Marco Govoni
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States.,Materials Science Division and Institute for Molecular Engineering , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Giulia Galli
- Institute for Molecular Engineering , University of Chicago , Chicago , Illinois 60637 , United States.,Materials Science Division and Institute for Molecular Engineering , Argonne National Laboratory , Lemont , Illinois 60439 , United States.,Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
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13
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Sjakste J, Tanimura K, Barbarino G, Perfetti L, Vast N. Hot electron relaxation dynamics in semiconductors: assessing the strength of the electron-phonon coupling from the theoretical and experimental viewpoints. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:353001. [PMID: 30084390 DOI: 10.1088/1361-648x/aad487] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The rapid development of the computational methods based on density functional theory, on the one hand, and of time-, energy-, and momentum-resolved spectroscopy, on the other hand, allows today an unprecedently detailed insight into the processes governing hot-electron relaxation dynamics, and, in particular, into the role of the electron-phonon coupling. Instead of focusing on the development of a particular method, theoretical or experimental, this review aims to treat the progress in the understanding of the electron-phonon coupling which can be gained from both, on the basis of recently obtained results. We start by defining several regimes of hot electron relaxation via electron-phonon coupling, with respect to the electron excitation energy. We distinguish between energy and momentum relaxation of hot electrons, and summarize, for several semiconductors of the IV and III-V groups, the orders of magnitude of different relaxation times in different regimes, on the basis of known experimental and numerical data. Momentum relaxation times of hot electrons become very short around 1 eV above the bottom of the conduction band, and such ultrafast relaxation mechanisms are measurable only in the most recent pump-probe experiments. Then, we give an overview of the recent progress in the experimental techniques allowing to obtain detailed information on the hot-electron relaxation dynamics, with the main focus on time-, energy-, and momentum-resolved photoemission experiments. The particularities of the experimental approach developed by one of us, which allows to capture time-, energy-, and momentum-resolved hot-electron distributions, as well as to measure momentum relaxation times of the order of 10 fs, are discussed. We further discuss the main advances in the calculation of the electron-phonon scattering times from first principles over the past ten years, in semiconducting materials. Ab initio techniques and efficient interpolation methods provide the possibility to calculate electron-phonon scattering times with high precision at reasonable numerical cost. We highlight the methods of analysis of the obtained numerical results, which allow to give insight into the details of the electron-phonon scattering mechanisms. Finally, we discuss the concept of hot electron ensemble which has been proposed recently to describe the hot-electron relaxation dynamics in GaAs, the applicability of this concept to other materials, and its limitations. We also mention some open problems.
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Affiliation(s)
- J Sjakste
- Laboratoire des Solides Irradiés, Ecole Polytechnique, CEA-DRF-IRAMIS, CNRS UMR 7642, 91120 Palaiseau, France
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14
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de Oliveira Neto PH, de Sousa LE. Activation Energies and Diffusion Coefficients of Polarons and Bipolarons in Organic Conductors. J Phys Chem A 2018; 122:5925-5930. [DOI: 10.1021/acs.jpca.8b04351] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pedro Henrique de Oliveira Neto
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Institute of Physics, University of Brasília, 70919-970 Brasília, Brazil
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15
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Kang D, Dai J. Dynamic electron-ion collisions and nuclear quantum effects in quantum simulation of warm dense matter. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:073002. [PMID: 29186001 DOI: 10.1088/1361-648x/aa9e29] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The structural, thermodynamic and transport properties of warm dense matter (WDM) are crucial to the fields of astrophysics and planet science, as well as inertial confinement fusion. WDM refers to the states of matter in a regime of temperature and density between cold condensed matter and hot ideal plasmas, where the density is from near-solid up to ten times solid density, and the temperature between 0.1 and 100 eV. In the WDM regime, matter exhibits moderately or strongly coupled, partially degenerate properties. Therefore, the methods used to deal with condensed matter and isolated atoms need to be properly validated for WDM. It is therefore a big challenge to understand WDM within a unified theoretical description with reliable accuracy. Here, we review the progress in the theoretical study of WDM with state-of-the-art simulations, i.e. quantum Langevin molecular dynamics and first principles path integral molecular dynamics. The related applications for WDM are also included.
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Affiliation(s)
- Dongdong Kang
- Department of Physics, National University of Defense Technology, Changsha, Hunan 410073, People's Republic of China
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16
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Abstract
Single-wall carbon nanotubes (SWNTs) have been extensively explored as an ultrafast nonlinear optical material. However, due to the numerous electronic and morphological arrangements, a simple and self-contained physical model that can unambiguously account for the rich photocarrier dynamics in SWNTs is still absent. Here, by performing broadband degenerate and non-degenerate pump-probe experiments on SWNTs of different chiralities and morphologies, we reveal strong evidences for the existence of bandgap renormalization in SWNTs. In particularly, it is found that the broadband transient response of SWNTs can be well explained by the combined effects of Pauli blocking and bandgap renormalization, and the distinct dynamics is further influenced by the different sensitivity of degenerate and non-degenerate measurements to these two concurrent effects. Furthermore, we attribute optical-phonon bath thermalization as an underlying mechanism for the observed bandgap renormalization. Our findings provide new guidelines for interpreting the broadband optical response of carbon nanotubes.
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17
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Caruso F, Hoesch M, Achatz P, Serrano J, Krisch M, Bustarret E, Giustino F. Nonadiabatic Kohn Anomaly in Heavily Boron-Doped Diamond. PHYSICAL REVIEW LETTERS 2017; 119:017001. [PMID: 28731743 DOI: 10.1103/physrevlett.119.017001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 06/07/2023]
Abstract
We report evidence of a nonadiabatic Kohn anomaly in boron-doped diamond, using a joint theoretical and experimental analysis of the phonon dispersion relations. We demonstrate that standard calculations of phonons using density-functional perturbation theory are unable to reproduce the dispersion relations of the high-energy phonons measured by high-resolution inelastic x-ray scattering. On the contrary, by taking into account nonadiabatic effects within a many-body field-theoretic framework, we obtain excellent agreement with our experimental data. This result indicates a breakdown of the Born-Oppenheimer approximation in the phonon dispersion relations of boron-doped diamond.
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Affiliation(s)
- Fabio Caruso
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, United Kingdom
- Institut für Physik and IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Moritz Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Philipp Achatz
- Université Grenoble Alpes, CNRS, Institut NEEL, F-38000 Grenoble, France
| | - Jorge Serrano
- Yachay Tech University, School of Physical Sciences and Nanotechnology, 100119-Urcuquí, Ecuador
| | - Michael Krisch
- European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex, France
| | - Etienne Bustarret
- Université Grenoble Alpes, CNRS, Institut NEEL, F-38000 Grenoble, France
| | - Feliciano Giustino
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, United Kingdom
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18
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Saidi WA, Poncé S, Monserrat B. Temperature Dependence of the Energy Levels of Methylammonium Lead Iodide Perovskite from First-Principles. J Phys Chem Lett 2016; 7:5247-5252. [PMID: 27973908 DOI: 10.1021/acs.jpclett.6b02560] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Environmental effects and intrinsic energy-loss processes lead to fluctuations in the operational temperature of solar cells, which can profoundly influence their power conversion efficiency. Here we determine from first-principles the effects of temperature on the band gap and band edges of the hybrid pervoskite CH3NH3PbI3 by accounting for electron-phonon coupling and thermal expansion. From 290 to 380 K, the computed band gap change of 40 meV coincides with the experimental change of 30-40 meV. The calculation of electron-phonon coupling in CH3NH3PbI3 is particularly intricate as the commonly used Allen-Heine-Cardona theory overestimates the band gap change with temperature, and excellent agreement with experiment is only obtained when including high-order terms in the electron-phonon interaction. We also find that spin-orbit coupling enhances the electron-phonon coupling strength but that the inclusion of nonlocal correlations using hybrid functionals has little effect. We reach similar conclusions in the metal-halide perovskite CsPbI3. Our results unambiguously confirm for the first time the importance of high-order terms in the electron-phonon coupling by direct comparison with experiment.
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Affiliation(s)
- Wissam A Saidi
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania, 15261, United States
| | - Samuel Poncé
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Bartomeu Monserrat
- Department of Physics and Astronomy, Rutgers University , Piscataway, New Jersey 08854-8019, United States
- TCM Group, Cavendish Laboratory, University of Cambridge , J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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19
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Monserrat B, Vanderbilt D. Temperature Effects in the Band Structure of Topological Insulators. PHYSICAL REVIEW LETTERS 2016; 117:226801. [PMID: 27925756 DOI: 10.1103/physrevlett.117.226801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Indexed: 06/06/2023]
Abstract
We study the effects of temperature on the band structure of the Bi_{2}Se_{3} family of topological insulators using first-principles methods. Increasing temperature drives these materials towards the normal state, with similar contributions from thermal expansion and from electron-phonon coupling. The band gap changes with temperature reach 0.3 eV at 600 K, of similar size to the changes caused by electron correlation. Our results suggest that temperature-induced topological phase transitions should be observable near critical points of other external parameters.
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Affiliation(s)
- Bartomeu Monserrat
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019, USA
- TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - David Vanderbilt
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019, USA
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20
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Chen W, Ambrosio F, Miceli G, Pasquarello A. Ab initio Electronic Structure of Liquid Water. PHYSICAL REVIEW LETTERS 2016; 117:186401. [PMID: 27835004 DOI: 10.1103/physrevlett.117.186401] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Indexed: 05/26/2023]
Abstract
Self-consistent GW calculations with efficient vertex corrections are employed to determine the electronic structure of liquid water. Nuclear quantum effects are taken into account through ab initio path-integral molecular dynamics simulations. We reveal a sizable band-gap renormalization of up to 0.7 eV due to hydrogen-bond quantum fluctuations. Our calculations lead to a band gap of 8.9 eV, in accord with the experimental estimate. We further resolve the ambiguities in the band-edge positions of liquid water. The valence-band maximum and the conduction-band minimum are found at -9.4 and -0.5 eV with respect to the vacuum level, respectively.
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Affiliation(s)
- Wei Chen
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Francesco Ambrosio
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Giacomo Miceli
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Alfredo Pasquarello
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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21
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Villegas CEP, Rocha AR, Marini A. Anomalous Temperature Dependence of the Band Gap in Black Phosphorus. NANO LETTERS 2016; 16:5095-101. [PMID: 27428304 DOI: 10.1021/acs.nanolett.6b02035] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Black phosphorus (BP) has gained renewed attention due to its singular anisotropic electronic and optical properties that might be exploited for a wide range of technological applications. In this respect, the thermal properties are particularly important both to predict its room temperature operation and to determine its thermoelectric potential. From this point of view, one of the most spectacular and poorly understood phenomena is indeed the BP temperature-induced band gap opening; when temperature is increased, the fundamental band gap increases instead of decreases. This anomalous thermal dependence has also been observed recently in its monolayer counterpart. In this work, based on ab initio calculations, we present an explanation for this long known and yet not fully explained effect. We show that it arises from a combination of harmonic and lattice thermal expansion contributions, which are in fact highly interwined. We clearly narrow down the mechanisms that cause this gap opening by identifying the peculiar atomic vibrations that drive the anomaly. The final picture we give explains both the BP anomalous band gap opening and the frequency increase with increasing volume (tension effect).
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Affiliation(s)
- Cesar E P Villegas
- Istituto di Struttura della Materia of the National Research Council , Via Salaria Km 29.3, I-00016 Monterotondo Stazione, Italy
- Instituto de Física Teórica, Universidade Estadual Paulista (UNESP) , Rua Dr. Bento T. Ferraz, 271, São Paulo, SP 01140-070, Brazil
| | - A R Rocha
- Instituto de Física Teórica, Universidade Estadual Paulista (UNESP) , Rua Dr. Bento T. Ferraz, 271, São Paulo, SP 01140-070, Brazil
| | - Andrea Marini
- Istituto di Struttura della Materia of the National Research Council , Via Salaria Km 29.3, I-00016 Monterotondo Stazione, Italy
- European Theoretical Spectroscopy Facility (ETSF), Via Salaria Km 29.3, I-00016 Monterotondo Stazione, Italy
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22
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Leng X, Jin F, Wei M, Ma Y. GW method and Bethe-Salpeter equation for calculating electronic excitations. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2016. [DOI: 10.1002/wcms.1265] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xia Leng
- School of Chemistry and Chemical Engineering; Shandong University; Jinan China
| | - Fan Jin
- School of Chemistry and Chemical Engineering; Shandong University; Jinan China
| | - Min Wei
- School of Chemistry and Chemical Engineering; Shandong University; Jinan China
| | - Yuchen Ma
- School of Chemistry and Chemical Engineering; Shandong University; Jinan China
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23
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Electron-vibration coupling induced renormalization in the photoemission spectrum of diamondoids. Nat Commun 2016; 7:11327. [PMID: 27103340 PMCID: PMC4844694 DOI: 10.1038/ncomms11327] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 03/16/2016] [Indexed: 01/03/2023] Open
Abstract
The development of theories and methods devoted to the accurate calculation of the electronic quasi-particle states and levels of molecules, clusters and solids is of prime importance to interpret the experimental data. These quantum systems are often modelled by using the Born–Oppenheimer approximation where the coupling between the electrons and vibrational modes is not fully taken into account, and the electrons are treated as pure quasi-particles. Here, we show that in small diamond cages, called diamondoids, the electron–vibration coupling leads to the breakdown of the electron quasi-particle picture. More importantly, we demonstrate that the strong electron–vibration coupling is essential to properly describe the overall lineshape of the experimental photoemission spectrum. This cannot be obtained by methods within Born–Oppenheimer approximation. Moreover, we deduce a link between the vibronic states found by our many-body perturbation theory approach and the well-known Jahn–Teller effect. The electron–vibration coupling is essential to describe the photoelectron properties of molecules. Here, the authors show theoretically and experimentally that the electron–vibration coupling is very large in diamonoids, and link the deduced vibronic states to the well-known Jahn–Teller effect.
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Poncé S, Gillet Y, Laflamme Janssen J, Marini A, Verstraete M, Gonze X. Temperature dependence of the electronic structure of semiconductors and insulators. J Chem Phys 2015; 143:102813. [PMID: 26374006 DOI: 10.1063/1.4927081] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The renormalization of electronic eigenenergies due to electron-phonon coupling (temperature dependence and zero-point motion effect) is sizable in many materials with light atoms. This effect, often neglected in ab initio calculations, can be computed using the perturbation-based Allen-Heine-Cardona theory in the adiabatic or non-adiabatic harmonic approximation. After a short description of the recent progresses in this field and a brief overview of the theory, we focus on the issue of phonon wavevector sampling convergence, until now poorly understood. Indeed, the renormalization is obtained numerically through a slowly converging q-point integration. For non-zero Born effective charges, we show that a divergence appears in the electron-phonon matrix elements at q → Γ, leading to a divergence of the adiabatic renormalization at band extrema. This problem is exacerbated by the slow convergence of Born effective charges with electronic wavevector sampling, which leaves residual Born effective charges in ab initio calculations on materials that are physically devoid of such charges. Here, we propose a solution that improves this convergence. However, for materials where Born effective charges are physically non-zero, the divergence of the renormalization indicates a breakdown of the adiabatic harmonic approximation, which we assess here by switching to the non-adiabatic harmonic approximation. Also, we study the convergence behavior of the renormalization and develop reliable extrapolation schemes to obtain the converged results. Finally, the adiabatic and non-adiabatic theories, with corrections for the slow Born effective charge convergence problem (and the associated divergence) are applied to the study of five semiconductors and insulators: α-AlN, β-AlN, BN, diamond, and silicon. For these five materials, we present the zero-point renormalization, temperature dependence, phonon-induced lifetime broadening, and the renormalized electronic band structure.
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Affiliation(s)
- S Poncé
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - Y Gillet
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - J Laflamme Janssen
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - A Marini
- Consiglio Nazionale delle Ricerche (CNR), Via Salaria Km 29.3, CP 10, 00016 Monterotondo Stazione, Italy
| | - M Verstraete
- European Theoretical Spectroscopy Facility and Physique des matériaux et nanostructures, Université de Liège, Allée du 6 Août 17, B-4000 Liège, Belgium
| | - X Gonze
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
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25
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Zacharias M, Patrick CE, Giustino F. Stochastic Approach to Phonon-Assisted Optical Absorption. PHYSICAL REVIEW LETTERS 2015; 115:177401. [PMID: 26551142 DOI: 10.1103/physrevlett.115.177401] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Indexed: 06/05/2023]
Abstract
We develop a first-principles theory of phonon-assisted optical absorption in semiconductors and insulators which incorporates the temperature dependence of the electronic structure. We show that the Hall-Bardeen-Blatt theory of indirect optical absorption and the Allen-Heine theory of temperature-dependent band structures can be derived from the present formalism by retaining only one-phonon processes. We demonstrate this method by calculating the optical absorption coefficient of silicon using an importance sampling Monte Carlo scheme, and we obtain temperature-dependent line shapes and band gaps in good agreement with experiment. The present approach opens the way to predictive calculations of the optical properties of solids at finite temperature.
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Affiliation(s)
- Marios Zacharias
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - Christopher E Patrick
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - Feliciano Giustino
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
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26
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Verdi C, Giustino F. Fröhlich Electron-Phonon Vertex from First Principles. PHYSICAL REVIEW LETTERS 2015; 115:176401. [PMID: 26551127 DOI: 10.1103/physrevlett.115.176401] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 06/05/2023]
Abstract
We develop a method for calculating the electron-phonon vertex in polar semiconductors and insulators from first principles. The present formalism generalizes the Fröhlich vertex to the case of anisotropic materials and multiple phonon branches, and can be used either as a postprocessing correction to standard electron-phonon calculations, or in conjunction with ab initio interpolation based on maximally localized Wannier functions. We demonstrate this formalism by investigating the electron-phonon interactions in anatase TiO(2), and show that the polar vertex significantly reduces the electron lifetimes and enhances the anisotropy of the coupling. The present work enables ab initio calculations of carrier mobilities, lifetimes, mass enhancement, and pairing in polar materials.
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Affiliation(s)
- Carla Verdi
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - Feliciano Giustino
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
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Leng X, Yin H, Liang D, Ma Y. Excitons and Davydov splitting in sexithiophene from first-principles many-body Green’s function theory. J Chem Phys 2015; 143:114501. [DOI: 10.1063/1.4930975] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Zhang X, Zhao M. Robust half-metallicity and topological aspects in two-dimensional Cu-TPyB. Sci Rep 2015; 5:14098. [PMID: 26365292 PMCID: PMC4568493 DOI: 10.1038/srep14098] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/18/2015] [Indexed: 11/17/2022] Open
Abstract
Half-metallicity due to the coexistence of metallic nature for one spin component and insulating nature for the other is a base of spintronics devices, but was only achieved in few materials. From first-principles calculations, we demonstrate that a recently-synthesized two-dimensional organometallic framework of 1,3,5-tris(pyridyl)benzene and Cu atoms (Cu-TPyB) has robust half-metallicity. High electron velocity in one spin channel at Dirac point and a relatively large band gap in the other make the material meeting the demand of filtering the current into a single spin component. Moreover, spin-orbit coupling induces topologically nontrivial band gaps in the vicinity of the Fermi level, which are implementable for achieving quantum anomalous Hall effect in a low temperature range (<8 K).
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Affiliation(s)
- Xiaoming Zhang
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Mingwen Zhao
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
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29
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Kawai H, Giorgi G, Marini A, Yamashita K. The mechanism of slow hot-hole cooling in lead-iodide perovskite: first-principles calculation on carrier lifetime from electron-phonon interaction. NANO LETTERS 2015; 15:3103-8. [PMID: 25807270 DOI: 10.1021/acs.nanolett.5b00109] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We report on an analysis of hot-carrier lifetimes from electron-phonon interaction in lead iodide perovskites using first-principles calculations. Our calculations show that the holes in CsPbI3 have very long lifetimes in the valence band region situated 0.6 eV below the top of the valence band. On the other hand, no long lifetime is predicted in PbI3(-). These different results reflect the different electronic density of states (DOSs) in the valence bands, that is, a small DOS for the former structure while a sharp DOS peak for the latter structure. We propose a reduction of the relaxation paths in the small valence DOS as being the origin of the slow hot-hole cooling. Analyzing the generalized Eliashberg functions, we predict that different perovskite A-site cations do not have an impact on the carrier decay mechanism. The similarity between the DOS structures of CsPbI3 and CH3NH3PbI3 enables us to extend the description of the decay mechanism of fully inorganic CsPbI3 to its organic-inorganic counterpart, CH3NH3PbI3.
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Affiliation(s)
- Hiroki Kawai
- †Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- ‡CREST-JST, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Giacomo Giorgi
- †Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- ‡CREST-JST, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
| | - Andrea Marini
- §Istituto di Struttura della Materia of the National Research Council and European Theoretical Spectroscopy Facility (ETSF), Via Salaria Km 29.3, I-00016 Monterotondo Stazione, Italy
| | - Koichi Yamashita
- †Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- ‡CREST-JST, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan
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30
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Chen W, Pasquarello A. First-principles determination of defect energy levels through hybrid density functionals and GW. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:133202. [PMID: 25744104 DOI: 10.1088/0953-8984/27/13/133202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this topical review, we discuss recent progress in electronic-structure methods for calculating defect energy levels in semiconductors and insulators. We concentrate mainly on two advanced electronic-structure schemes, namely hybrid density functional theory and many-body perturbation theory in the GW approximation. These two schemes go beyond standard density functional theory in the semilocal approximation providing a more realistic description of band gaps. In particular, we address important aspects underlying the GW scheme and highlight the correspondence between the defect levels as obtained in the various schemes. We further assess the quality of the band-edge positions determined with hybrid functionals and GW through the calculation of band-offsets at semiconductor heterojunctions and of ionization potentials at semiconductor surfaces.
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Affiliation(s)
- Wei Chen
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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31
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Cudazzo P, Sottile F, Rubio A, Gatti M. Exciton dispersion in molecular solids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:113204. [PMID: 25738755 DOI: 10.1088/0953-8984/27/11/113204] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The investigation of the exciton dispersion (i.e. the exciton energy dependence as a function of the momentum carried by the electron-hole pair) is a powerful approach to identify the exciton character, ranging from the strongly localised Frenkel to the delocalised Wannier-Mott limiting cases. We illustrate this possibility at the example of four prototypical molecular solids (picene, pentacene, tetracene and coronene) on the basis of the parameter-free solution of the many-body Bethe-Salpeter equation. We discuss the mixing between Frenkel and charge-transfer excitons and the origin of their Davydov splitting in the framework of many-body perturbation theory and establish a link with model approaches based on molecular states. Finally, we show how the interplay between the electronic band dispersion and the exchange electron-hole interaction plays a fundamental role in setting the nature of the exciton. This analysis has a general validity holding also for other systems in which the electron wavefunctions are strongly localized, as in strongly correlated insulators.
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Affiliation(s)
- Pierluigi Cudazzo
- Nano-Bio Spectroscopy group, Universidad del País Vasco, CFM CSIC-UPV/EHU-MPC and DIPC, E-20018 San Sebastián, Spain. European Theoretical Spectroscopy Facility (ETSF
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32
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Forero-Martinez NC, Thi Le HL, Ning N, Vach H, Weissker HC. Temperature dependence of the radiative lifetimes in Ge and Si nanocrystals. NANOSCALE 2015; 7:4942-4948. [PMID: 25690749 DOI: 10.1039/c4nr04905e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effect of finite temperature on the optical properties of nanostructures has been a longstanding problem for their theoretical description and its omission presents serious limits on the validity of calculated spectra and radiative lifetimes. Most ab initio calculations have been carried out neglecting temperature effects altogether, although progress has been made recently. In the present work, the temperature dependence of the intrinsic radiative lifetimes of excited electron-hole pairs in Ge and Si nanocrystals due to classical temperature effects is calculated using ab initio molecular dynamics. Fully hydrogen-saturated Ge and Si nanocrystals without surface reconstructions show opposite behavior: the very short lifetimes in Ge increase with temperature, while the much longer ones in Si decrease. However, the temperature effect is found to be strongly dependent on the surface structure: surface reconstructions cause partial localization of the wave functions and override the difference between Si and Ge. As a consequence, the temperature dependence in reconstructed nanocrystals is strongly attenuated compared to the fully saturated nanocrystals. Our calculations are an important step towards predictive modeling of the optical properties of nanostructures.
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Patrick CE, Giustino F. Unified theory of electron-phonon renormalization and phonon-assisted optical absorption. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:365503. [PMID: 25134725 DOI: 10.1088/0953-8984/26/36/365503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a theory of electronic excitation energies and optical absorption spectra which incorporates energy-level renormalization and phonon-assisted optical absorption within a unified framework. Using time-independent perturbation theory we show how the standard approaches for studying vibronic effects in molecules and those for addressing electron-phonon interactions in solids correspond to slightly different choices for the non-interacting Hamiltonian. Our present approach naturally leads to the Allen-Heine theory of temperature-dependent energy levels, the Franck-Condon principle, the Herzberg-Teller effect and to phonon-assisted optical absorption in indirect band gap materials. In addition, our theory predicts sub-gap phonon-assisted optical absorption in direct gap materials, as well as an exponential edge which we tentatively assign to the Urbach tail. We also consider a semiclassical approach to the calculation of optical absorption spectra which simultaneously captures energy-level renormalization and phonon-assisted transitions and is especially suited to first-principles electronic structure calculations. We demonstrate this approach by calculating the phonon-assisted optical absorption spectrum of bulk silicon.
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Yin H, Ma Y, Hao X, Mu J, Liu C, Yi Z. Quasiparticle electronic structure and optical absorption of diamond nanoparticles from ab initio many-body perturbation theory. J Chem Phys 2014; 140:214315. [PMID: 24908016 DOI: 10.1063/1.4880695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The excited states of small-diameter diamond nanoparticles in the gas phase are studied using the GW method and Bethe-Salpeter equation (BSE) within the ab initio many-body perturbation theory. The calculated ionization potentials and optical gaps are in agreement with experimental results, with the average error about 0.2 eV. The electron affinity is negative and the lowest unoccupied molecular orbital is rather delocalized. Precise determination of the electron affinity requires one to take the off-diagonal matrix elements of the self-energy operator into account in the GW calculation. BSE calculations predict a large exciton binding energy which is an order of magnitude larger than that in the bulk diamond.
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Affiliation(s)
- Huabing Yin
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Yuchen Ma
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Xiaotao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Jinglin Mu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Chengbu Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Zhijun Yi
- Department of Physics, China University of Mining and Technology, Xuzhou 221116, China
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Klimeš J, Kresse G. Kohn-Sham band gaps and potentials of solids from the optimised effective potential method within the random phase approximation. J Chem Phys 2014; 140:054516. [DOI: 10.1063/1.4863502] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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36
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Bruneval F, Gatti M. Quasiparticle Self-Consistent GW Method for the Spectral Properties of Complex Materials. Top Curr Chem (Cham) 2014; 347:99-135. [DOI: 10.1007/128_2013_460] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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37
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Quantum simulation of thermally-driven phase transition and oxygen K-edge x-ray absorption of high-pressure ice. Sci Rep 2013; 3:3272. [PMID: 24253589 PMCID: PMC3834560 DOI: 10.1038/srep03272] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/31/2013] [Indexed: 11/09/2022] Open
Abstract
The structure and phase transition of high-pressure ice are of long-standing interest and challenge, and there is still a huge gap between theoretical and experimental understanding. The quantum nature of protons such as delocalization, quantum tunneling and zero-point motion is crucial to the comprehension of the properties of high-pressure ice. Here we investigated the temperature-induced phase transition and oxygen K-edge x-ray absorption spectra of ice VII, VIII and X using ab initio path-integral molecular dynamics simulations. The tremendous difference between experiments and the previous theoretical predictions is closed for the phase diagram of ice below 300 K at pressures up to 110 GPa. Proton tunneling assists the proton-ordered ice VIII to transform into proton-disordered ice VII where only thermal activated proton-transfer cannot occur. The oxygen K edge with its shift is sensitive to the order-disorder transition, and therefore can be applied to diagnose the dynamics of ice structures.
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38
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Quantum nuclear dynamics in the photophysics of diamondoids. Nat Commun 2013; 4:2006. [DOI: 10.1038/ncomms3006] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 05/14/2013] [Indexed: 11/08/2022] Open
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39
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Marini A. Competition between the electronic and phonon–mediated scattering channels in the out–of–equilibrium carrier dynamics of semiconductors: an ab-initio approach. ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/427/1/012003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Vukmirović N, Bruder C, Stojanović VM. Electron-phonon coupling in crystalline organic semiconductors: microscopic evidence for nonpolaronic charge carriers. PHYSICAL REVIEW LETTERS 2012; 109:126407. [PMID: 23005969 DOI: 10.1103/physrevlett.109.126407] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Indexed: 06/01/2023]
Abstract
We consider electron-phonon coupling in crystalline organic semiconductors, using naphthalene for our case study. Employing a first-principles approach, we compute the changes in the selfconsistent Kohn-Sham potential corresponding to different phonon modes and go on to obtain the carrier-phonon coupling matrix elements (vertex functions). We then evaluate perturbatively the quasiparticle spectral residues for electrons at the bottom of the lowest unoccupied (LUMO), and holes at the top of the highest occupied (HOMO), band, obtaining Z(e) ≈ 0.74 and Z(h) ≈ 0.78, respectively. Along with the widely accepted notion that the carrier-phonon coupling strengths in polyacenes decrease with increasing molecular size, our results provide strong microscopic evidence for the previously conjectured nonpolaronic nature of bandlike carriers in these systems.
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Affiliation(s)
- Nenad Vukmirović
- Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Serbia.
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Patrick CE, Giustino F. GW quasiparticle bandgaps of anatase TiO2 starting from DFT + U. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:202201. [PMID: 22510587 DOI: 10.1088/0953-8984/24/20/202201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigate the quasiparticle band structure of anatase TiO(2), a wide gap semiconductor widely employed in photovoltaics and photocatalysis. We obtain GW quasiparticle energies starting from density-functional theory (DFT) calculations including Hubbard U corrections. Using a simple iterative procedure we determine the value of the Hubbard parameter yielding a vanishing quasiparticle correction to the fundamental bandgap of anatase TiO(2). The bandgap (3.3 eV) calculated using this optimal Hubbard parameter is smaller than the value obtained by applying many-body perturbation theory to standard DFT eigenstates and eigenvalues (3.7 eV). We extend our analysis to the rutile polymorph of TiO(2) and reach similar conclusions. Our work highlights the role of the starting non-interacting Hamiltonian in the calculation of GW quasiparticle energies in TiO(2) and suggests an optimal Hubbard parameter for future calculations.
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