Freiburg 2019 – wissenschaftliches Programm

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FM: Fall Meeting

FM 66: Poster: Entanglement

FM 66.4: Poster

Mittwoch, 25. September 2019, 16:30–18:30, Tents

Initial-state dependence of the long-time dynamics in a spin-boson system — •Sebastian Wenderoth and Michael Thoss — Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany

Thermalization of a system refers to the process of approaching a unique steady state that depends only on a few macroscopic observables. Triggered by the development of new experimental tools, the question how an isolated quantum system can equilibrate to such a state under its own dynamics has recently received renewed interest. Various numerical studies suggest that subsystems of isolated quantum systems can equilibrate under unitary time evolution. This relaxation is caused by the remainder of the system acting as an effective bath. However, as the hybridization between the subsystem and the remainder increases this simple picture breaks down and the influence of the remainder on the subsystem can change qualitatively.

Inspired by a recent experiment with trapped-ions [1], we investigate a special type of a spin-boson model. Employing the multilayer multiconfiguration time dependent Hartree method [2], we simulate the dynamics of the system in a numerically exact way. As a function of the spin-boson coupling, we observe a qualitative change of the dynamics of the spin, induced by the coupling to the bosonic modes, ranging from the usual relaxation dynamics for small couplings to non-stationary long-time states of the spin that depend on its initial state.

[1] G.Glos et al., Phys. Rev. Lett. 117, 170401 (2016)

[2] H. Wang et al., J. Chem. Phys. 119, 1289 (2003)