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arXiv · 1203.5994

Quantum thermometry using the ac Stark shift within the Rabi model

Kieran D. B. Higgins·Brendon W. Lovett·Erik M. Gauger
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Abstract

A quantum two level system coupled to a harmonic oscillator represents a ubiquitous physical system. New experiments in circuit QED and nano-electromechanical systems (NEMS) achieve unprecedented coupling strength at large detuning between qubit and oscillator, thus requiring a theoretical treatment beyond the Jaynes Cummings model. Here we present a new method for describing the qubit dynamics in this regime, based on an oscillator correlation function expansion of a non-Markovian master equation in the polaron frame. Our technique yields a new numerical method as well as a succinct approximate expression for the qubit dynamics. We obtain a new expression for the ac Stark shift and show that this enables practical and precise qubit thermometry of an oscillator.

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Kieran D. B. Higgins, Brendon W. Lovett, Erik M. Gauger. 2012-03-27. Quantum thermometry using the ac Stark shift within the Rabi model. https://doi.org/10.1103/physrevb.88.155409

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