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HL: Fachverband Halbleiterphysik
HL 7: (Quantum) Transport Properties
HL 7.1: Vortrag
Montag, 5. September 2022, 15:00–15:15, H31
A new Time-Domain Approach for Linear Responses and Electrical Conductivity — •Michel Panhans1,2 and Frank Ortmann1,2 — 1Department of Chemistry, TU München — 2Center for Advancing Electronics Dresden, TU Dresden
Linear-response theory is a powerful theoretical framework to investigate, e.g., electrical and magnetic transport and to compare theory with experiments. Many intriguing quantum-transport phenomena such as quantum Hall effects, spin Hall effects, and quantum spin Hall effects have been derived within this framework. Beyond the general theory, strong efforts have been spent in the last decade to develop efficient and accurate computational methods to calculate charge transport in condensed matter. [1] In our recent work, we present a new time-domain approach to calculate arbitrary linear responses, which is based on a decomposition of the general Kubo formula into time-symmetric and time-antisymmetric parts. [2] The new algorithm is at least 1000 times faster compared to former time evolution schemes. [3] As a showcase, we have investigated the quantum anomalous Hall effect of the disordered Haldane model, where the quantum dynamics of the topological state have been analyzed. The proposed theory and the computational method provide a promising route to access transport phemomena in complpex and topological systems.
[1] Z. Fan et al., Physics Reports, 903, 1-69 (2021)
[2] M. Panhans and F. Ortmann, Phys. Rev. Lett. 127, 016601 (2021)
[3] F. Ortmann et al., Phys. Rev. B 91, 165117 (2015)