Stochastic collisional quantum thermometry

TL;DR

This paper extends collisional quantum thermometry to include stochastic waiting times, demonstrating that randomness can enhance parameter estimation and that local measurements suffice, negating the need for quantum correlations.

Contribution

It introduces stochastic waiting times into collisional thermometry, showing improved parameter range and that local measurements are sufficient for optimality.

Findings

Random waiting times extend the thermometry advantage.

Local measurements are sufficient for optimal estimation.

The advantage holds for both dephasing and partial swap interactions.

Abstract

We extend collisional quantum thermometry schemes to allow for stochasticity in the waiting time between successive collisions. We establish that introducing randomness through a suitable waiting time distribution, the Weibull distribution, allows to significantly extend the parameter range for which an advantage over the thermal Fisher information is attained. These results are explicitly demonstrated for dephasing interactions and also hold for partial swap interactions. Furthermore, we show that the optimal measurements can be performed locally, thus implying that genuine quantum correlations do not play a role in achieving this advantage. We explicitly confirm this by examining the correlation properties for the deterministic collisional model.