Quantum Limits of Thermometry

TL;DR

This paper demonstrates that quantum thermometry can theoretically surpass classical shot noise limits, achieving a Heisenberg limit of precision scaling as 1/N by mapping thermometry to phase estimation.

Contribution

It introduces a quantum approach to thermometry that can reach the Heisenberg limit, surpassing traditional shot noise constraints.

Findings

Thermometry precision can be improved to 1/N scaling.

Mapping thermometry to phase estimation enables quantum-enhanced accuracy.

Heisenberg limit is theoretically achievable in quantum thermometry.

Abstract

The precision of typical thermometers consisting of $N$ particles is shot noise limited, improving as $\sim1/\sqrt{N}$. For high precision thermometry and thermometric standards this presents an important theoretical noise floor. Here it is demonstrated that thermometry may be mapped onto the problem of phase estimation, and using techniques from optimal phase estimation, it follows that the scaling of the precision of a thermometer may in principle be improved to $\sim1/N$, representing a Heisenberg limit to thermometry.