Mainz 2017 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 31: Poster: Quantum Optics and Photonics I

Q 31.8: Poster

Dienstag, 7. März 2017, 17:00–19:00, P OG1+2

Dynamics of a one-dimensional two-component Bose gas quenched to criticality. — •Martin Rabel, Markus Karl, and Thomas Gasenzer — Kirchhoff-Institut für Physik, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany

We study the dynamics of a two-component Bose gas after a parameter quench into the proximity of a quantum critical point using analytical, real-time effective-action techniques. The relative degrees of freedom within the system can be described by a quasi-spin 1/2 model. This model is subject to a mean-field paramagnetic to ferromagnetic quantum phase transition. For the full model this corresponds to a transition from a miscible to an immiscible phase. The transition is investigated in a dynamical setup: The initial state is the ground-state configuration far away from criticality. Following a sudden quench to criticality the time evolution of the emerging spin fluctuations is analysed. In the one-dimensional system under investigation, the non-vanishing energy introduced by the quench leads to a finite correlation length during the induced time evolution. The finite critical correlation length is determined within a leading-order 1/N approximation. The obtained analytical results are compared with Truncated-Wigner numerical simulations.