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arXiv · 2206.08410

Critical Quantum Metrology in the Non-Linear Quantum Rabi Model

Zu-Jian Ying·Simone Felicetti·Gang Liu·Daniel Braak
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Abstract

The quantum Rabi model (QRM) with linear coupling between light mode and qubit exhibits the analog of a second order phase transition for vanishing mode frequency which allows for criticality-enhanced quantum metrology in a few-body system. We show that the QRM including a non-linear coupling term exhibits much higher measurement precisions due to its first order like phase transition at \emph{finite} frequency, avoiding the detrimental slowing-down effect close to the critical point of the linear QRM. When a bias term is added to the Hamiltonian, the system can be used as a fluxmeter or magnetometer if implemented in circuit QED platforms.

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Zu-Jian Ying, Simone Felicetti, Gang Liu, Daniel Braak. 2022-06-16. Critical Quantum Metrology in the Non-Linear Quantum Rabi Model. https://doi.org/10.3390/e24081015

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