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Register a new userDissipation-induced enhancement and squeezing of quantum fluctuations
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Added by
Gianluca Rastelli Dr.
Publication date
2016
fields
Physics
and research's language is
English
Authors
G. Rastelli
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We study a quantum harmonic oscillator linearly coupled through the position operator $hat{q}$ to a first bath and through the momentum operator $hat{p}$ to a second bath yielding an Ohmic-Drude dissipation. We analyse the oscillators 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 relevant regimes corresponding to the low temperature limit and when the Drude high frequency cutoff is much larger than all other frequencies. At low temperature, each bath operates to suppress the oscillators ground state quantum fluctuations ${langle Delta hat{q}^2 rangle}_0$ or ${langle Delta hat{p}^2 rangle}_0$ 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 can be enhanced by increasing the dissipative coupling.
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