# SKM 2023 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# DY: Fachverband Dynamik und Statistische Physik

## DY 43: Poster: Quantum Dynamics and Many-Body Systems

### DY 43.1: Poster

### Donnerstag, 30. März 2023, 13:00–16:00, P1

applications of generalized coherent states in bosonic systems — •yulong qiao^{1}, Frank Grossman^{2}, and Joonsuk Huh^{3} — ^{1}Institute for theoretical physics, TU Dresden, 01062 Dresden, Germany — ^{2}Institute for theoretical physics, TU Dresden, 01062 Dresden, Germany — ^{3}Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea

Generalized coherent states (GCS) are found to be very useful for studying bosonic systems with a fixed number of particles, such as the Bose-Hubbard model and boson sampling. Firstly, we present the non-equilibrium dynamics of the Bose-Hubbard model based on the time-dependent variational principle [1]. Increasing the multiplicity of GCS leads to converged results quickly for weak interaction strength, which indicates that GCS are a well-suited basis in the superfuild phase. Secondly, we investigate the boson sampling problem whose input state is a Fock state. Using an exact expansion of the Fock state in terms of GCS, we obtain the output state by means of a unitary rotation. By this process the total information is contained in a finite number of GCS. The specific structure of the GCS allows us to split the whole system into two parts easily and to study the entanglement entropy of the output state in detail [2].

[1] Y. Qiao and F. Grossmann, Exact variational dynamics of the multimode Bose-Hubbard model based on SU(M) coherent states, Phys. Rev. A 103, 042209 (2021).

[2] Y. Qiao, J. Huh, F. Grossmann, Entanglement in the full state vector of boson sampling, arXiv:2210.09915 [quant- ph] (2022).