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Friday, April 12th 2019

2:30 pm:

Many-body interactions lead to unexpected effects in the open

Bose-Hubbard model. When the model is subjected to local loss, particle

currents are induced. Away from the dissipative site the currents start

to reverse their direction at intermediate and long times. This leads

to a metastable state with a total particle current pointing away from

the dissipative site. We studied the model numerically by combining

a quantum trajectory approach with a density-matrix renormalization

group scheme. An alternative equation of motion approach based on

an effective fermion model shows that the reversal of currents can be

understood qualitatively by the creation of holon-doublon pairs at the

edge of the region of reduced particle density. The doublons are then

able to escape while the holes move towards the dissipative site.

Some keywords for the talk:

1D quantum chains, Bose-Hubbard model, Markovian open systems,

Matrix product states/ Density Matrix Renormalization Group

, Metastable states, Lindblad master equation

Papers and readings:

His results have been published on

M. Kiefer-Emmanouilidis & J. Sirker, Current reversals and metastable states in the infinite Bose-Hubbard chain with local particle loss. PhysRevA.96.063625 (2017).

The following books give a quite good introduction to open systems:

1. Breuer, Heinz-Peter; Petruccione, F. (2002). The Theory of Open Quantum Systems. Oxford University Press

2. Carmichael, Howard. An Open Systems Approach to Quantum Optics

3. Further there is a quite good but mathematically summary here

https://en.wikiversity.org/wiki/Category:Open_Quantum_Systems/Lectures

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