Few-fermion thermometry

TL;DR

This paper proposes a quantum thermometer using a few-fermion system in a 1D trap, demonstrating high sensitivity near the fundamental limit at nanokelvin temperatures.

Contribution

It introduces a theoretical model for a fermionic quantum thermometer with tunable interactions achieving near-optimal temperature sensitivity.

Findings

High sensitivity close to fundamental bounds

Control of interaction strength enhances sensitivity

Feasible experimental coupling discussed

Abstract

Potential realization of a quantum thermometer operating in the nanokelvin regime, formed by a few-fermionic mixture confined in a one-dimensional harmonic trap, is proposed. Thermal states of the system are studied theoretically from the point of view of fundamental sensitivity to temperature changes. It is pointed out that the ability to control the interaction strength in such systems allows obtaining high-temperature sensitivity in the regime where the temperature is much lower than the characteristic temperature scale determined by a harmonic confinement. This sensitivity is very close to the fundamental bound that involves optimal engineering of level separations. The performance of practical measurement schemes and the possible experimental coupling of the thermometer to the probe are discussed.