Langevin simulations of a long-range electron-phonon model
| Autor: | Richard T. Scalettar, G. G. Batrouni |
|---|---|
| Přispěvatelé: | Institut de Physique de Nice (INPHYNI), Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Phonon
74.70.Xa Quantum Monte Carlo FOS: Physical sciences 02 engineering and technology 75.40.Mg 01 natural sciences Electronic structure and strongly correlated systems symbols.namesake Condensed Matter - Strongly Correlated Electrons Quantum mechanics 0103 physical sciences 010306 general physics ComputingMilieux_MISCELLANEOUS Boson [PHYS]Physics [physics] Physics Strongly Correlated Electrons (cond-mat.str-el) 71.10.Fd Fermion 021001 nanoscience & nanotechnology Imaginary time 74.20.Rp [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph] Langevin equation symbols 0210 nano-technology Hamiltonian (quantum mechanics) Charge density wave |
| Zdroj: | Physical Review B Physical Review B, American Physical Society, 2019, 99 (3), pp.035114. ⟨10.1103/PhysRevB.99.035114⟩ Phys.Rev.B Phys.Rev.B, 2019, 99 (3), pp.035114. ⟨10.1103/PhysRevB.99.035114⟩ Physical Review B, American Physical Society, 2019, 99 (3), ⟨10.1103/PhysRevB.99.035114⟩ |
| ISSN: | 2469-9950 2469-9969 |
| DOI: | 10.1103/PhysRevB.99.035114⟩ |
| Popis: | We present a quantum Monte Carlo (QMC) study, based on the Langevin equation, of a Hamiltonian describing electrons coupled to phonon degrees of freedom. The bosonic part of the action helps control the variation of the field in imaginary time. As a consequence, the iterative conjugate gradient solution of the fermionic action, which depends on the boson coordinates, converges more rapidly than in the case of electron-electron interactions, such as the Hubbard Hamiltonian. Fourier acceleration is shown to be a crucial ingredient in reducing the equilibration and autocorrelation times. After describing and benchmarking the method, we present results for the phase diagram focusing on the range of the electron-phonon interaction. We delineate the regions of charge density wave formation from those in which the fermion density is inhomogeneous, caused by phase separation. We show that the Langevin approach is more efficient than the determinant QMC method for lattice sizes $N\ensuremath{\gtrsim}8\ifmmode\times\else\texttimes\fi{}8$ and that it therefore opens a potential path to problems including, for example, charge order in the three-dimensional Holstein model. |
| Databáze: | OpenAIRE |
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