Dresden 2017 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 6: Many-Body Quantum Systems (joint session DY/TT)

DY 6.7: Vortrag

Montag, 20. März 2017, 11:45–12:00, ZEU 118

Dissipation-induced enhancement of quantum fluctuations — •Gianluca Rastelli — University of Konstanz Fachbereich Physik, Fach 703 D-78457 Konstanz

We study a quantum harmonic oscillator linearly coupled through the position operator q to a first bath and through the momentum operator p to a second bath. We analyse the oscillator’s fluctuations as a function of the ratio between the strength of the two couplings, focusing in particular on the situation in which the two dissipative interactions are comparable. Analytic formulas are derived in the low temperature limit [1]. In this regime, each bath operates to suppress the oscillator’s ground state quantum fluctuations for q or p, viz. the operator appearing in the corresponding interaction. When one of the two dissipative interactions dominates over the other, the fluctuations for the coupling operator are squeezed. When the two interactions are comparable, the two baths enter in competition as the two conjugate operators do not commute yielding quantum frustration. In this regime, remarkably, the fluctuations of both two quadratures are enhanced by increasing the dissipative coupling. [1] G. Rastelli, New J. Phys. 18, 053033 (2016).