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arXiv · 2103.00877

Pulsed characteristic-function measurement of a thermalizing harmonic oscillator

Ralf Betzholz·Yu Liu·Jianming Cai
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Abstract

We present a method for the direct measurement of the Wigner characteristic function of a thermalizing harmonic oscillator that is completely inaccessible for control or measurement. The strategy employs a recently proposed probe-measurement-based scheme [Phys. Rev. Lett. 122, 110406 (2019)] which relies on the pulsed control of a two-level probe. We generalize this scheme to the case of a nonunitary time evolution of the target harmonic oscillator, describing its thermalization through contact to a finite-temperature environment, given in the form of a Lindblad master equation. This generalization is achieved using a superoperator formalism and yields analytical expressions for the direct measurement of the characteristic function, accounting for the decoherence during the measurement process.

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Ralf Betzholz, Yu Liu, Jianming Cai. 2021-03-01. Pulsed characteristic-function measurement of a thermalizing harmonic oscillator. https://doi.org/10.1103/physreva.104.012421

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