Fleischhauer, Michael

Date:  Thursday, December 15, 2016
Time: 16:00
Place: ETH Zurich, Hönggerberg, HPV G 5
Host:  Atac Imamoglu

Topological order in finite-temperature and driven dissipative systems

Michael Fleischhauer
Universität Kaiserslautern, Germany

I introduce a classification scheme for topological phases applicable to finite-temperature states as well as stationary states of driven, dissipative systems based on a generalization of the many-body polarization. The polarization can be used to probe the topological properties of non-interacting and interacting closed and open systems alike  and remains a meaningful quantity even in the presence of moderate particle-number fluctuations. As examples, I discuss an open-system version of a topological Thouless pump in the steady state of one-dimensional lattices driven by Markovian reservoirs [1 ]and the finite-temperature Rice-Mele and Hofstadter-Hubbard models. Here a non-trivial winding of the many-body polarization identifies topological invariants. The winding is shown to be robust against Hamiltonian perturbations as well as homogeneous dephasing and particle losses. I will also discuss a measurement scheme that allows to detect the polarization winding of finite-temperature and driven, dissipative systems through a quantized transport in an auxiliary quantum system.

[1] D. Linzner et al., Phys. Rev. B 94, 201105 (2016)