Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 19: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems 2 (jointly with DY)

TT 19.2: Vortrag

Montag, 16. März 2015, 15:15–15:30, H 3010

Auxiliary master equation approach to nonequilibrium correlated impurities: a matrix product states treatment — •Antonius Dorda, Martin Ganahl, Hans Gerd Evertz, Wolfgang von der Linden, and Enrico Arrigoni — Graz University of Technology, Graz, Austria

The auxiliary master equation approach [1,2] allows for a direct and efficient calculation of steady state properties of correlated impurity problems out of equilibrium, as is needed e.g. for nonequilibrium dynamical mean field theory [3]. The basic idea is to replace the original impurity problem by an auxiliary one, described by an open quantum system consisting of a finite number of bath sites embedded in a Markovian environment. The system dynamics are then described by a Lindblad equation, in which the different bath parameters are optimized by fitting the bath hybridization function in Keldysh space. Upon increasing the number of bath sites, the results can be systematically improved and the solution of the auxiliary system converges towards the exact one. A systematic study using a non-Hermitian Lanczos solver has been carried out [1] and a good agreement with reference values was found already for rather small system sizes. In order to further increase the accuracy, matrix product states are employed to address the interacting Lindblad problem, which enables one to consider larger system sizes.

[1] A. Dorda et al., Phys. Rev. B 89, 165105 (2014)

[2] E. Arrigoni et al., Phys. Rev. Lett. 110, 086403 (2013)

[3] J. K. Freericks et al., Phys. Rev. Lett. 97, 266408 (2006)