Rostock 2019 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 62: Optomechanics
Q 62.7: Vortrag
Freitag, 15. März 2019, 12:15–12:30, S SR 111 Maschb.
Tuning the Order of the Nonequilibrium Quantum Phase Transition in a HybridAtom-Optomechanical System — •Niklas Mann1, Axel Pelster2, and Michael Thorwart1 — 1I. Institut für Theoretische Physik, Universität Hamburg, Jungiustraße 9, 20355 Hamburg, Germany — 2Physics Department and Research Center OPTIMAS, Technische Universität Kaiserslautern, Erwin-Schrödinger Straße 46, 67663 Kaiserslautern, Germany
A quantum many-body hybrid system is considered formed by a nanomembrane, which interacts optomechanically with light in a pumped cavity, and an ultracold atom gas in the
optical lattice of the out-coupled light.
An effective atom-membrane coupling can be realized in two different ways: first, the membrane is coupled to the motion of the atoms in the lattice1 and, second, the motion of the membrane is coupled to transitions between two internal atomic states2.
By tuning the applied laser intensity, the optomechanical coupling of the membrane motion to the atomic motional or internal states can be tuned and a nonequilibrium quantum phase transition occurs above a critical intensity.
Focussing on the latter case, the nonequilibrium quantum phase transition is characterized by a sizeable occupation of the energetically higher internal states and a displaced membrane.
In contrast to the motional coupling scheme, its order can be changed by tuning the transition frequency.
1 N. Mann, M. Reza Bakhtiari, A. Pelster, M. Thorwart, Phys. Rev. Lett. 120, 063605 (2018)
2 N. Mann, A. Pelster, M. Thorwart, submitted (arXiv:1810.12846)