22. Mai 2017 , 16:00 - 17:00 Uhr

The generalized Dicke model with broken parity symmetry

Seminar: Current problems in theoretical physics

Sprecher: Kristopher Rasek, TU Dortmund

The Dicke model describes a coupled System of a spin of arbitrary length and a bosonic mode.
Originally intended to describe  a radiating gas, it became of interest for its quantum phase transition and analytical accessibility in the classical limit.

I consider a generalized model, in which the parity symmetry, which causes the phase transition, can be broken.
Breaking the parity allows us to study the nature of the phase transition and to generalize previous research, for example analyzing quantum chaos via quantum invariants.

For the transition to the classical limit, a Poincaré Husimi projection is used and the time evolution of initially coherent states is analyzed.
Numerical methods include sparse matrix diagonalization using the FEAST algorithm and time evolution via Chebyshev expansion.