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arXiv · 1510.08111

Achieving the Landau bound to precision of quantum thermometry in systems with vanishing gap

Matteo G. A. Paris
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Abstract

We address estimation of temperature for finite quantum systems at thermal equilibrium and show that the Landau bound to precision $δT^2 \propto T^2$, originally derived for a classical {\em not too small} system being a portion of a large isolated system at thermal equilibrium, may be also achieved by energy measurement in microscopic {\em quantum} systems exhibiting vanishing gap as a function of some control parameter. On the contrary, for any quantum system with a non-vanishing gap $Δ$, precision of any temperature estimator diverges as $δT^2 \gtrsim T^4 e^{Δ/T}$.

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Matteo G. A. Paris. 2016-01-14. Achieving the Landau bound to precision of quantum thermometry in systems with vanishing gap. https://doi.org/10.1088/1751-8113%2F49%2F3%2F03lt02

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