Berlin 2024 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 59: Transport: Poster

TT 59.17: Poster

Wednesday, March 20, 2024, 15:00–18:00, Poster E

Relaxation dynamics of quantum many-body systems with phonon degrees of freedom using the multi-trajectory Ehrenfest method — •Heiko Georg Menzler, Suman Mondal, and Fabian Heidrich-Meisner — Georg-August-Universität Göttingen

As the primary goal of our research we want to study the delocalization of interacting electrons in the presence of disorder and phonons, that is the stability of many-body localization in a solid-state environment. However, large mixed bosonic-fermionic Hilbert spaces make full quantum solutions numerically costly. Therefore, we want to analyze the model in the multi-trajectory Ehrenfest (MTE) formalism in the limit of adiabatic (slow) phonons by treating the phonons classically. We apply this formalism to study the decay of spatially inhomogeneous particle distributions as a function of electron-phonon coupling. As a main result, we observe a delocalization at sufficiently long times and strong electron-phonon coupling. The core idea of the MTE method---which is a well established method in quantum chemistry---is to separate fast and slow degrees of freedom while the slow phononic environment is treated in the classical limit. In this project we extend the established methodology to deal with many-body electron subsystems by implementing time-dependent Lanczos and TEBD time evolution in conjunction with MTE and use this new take on the MTE method to analyze disordered system in the presence of phonons.

This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via FOR 5522 and SFB 1073.

Keywords: Thermalization; Phonons; Semiclassical Method; Transport; Electron-Phonon coupling