Topological quantum thermometry

TL;DR

This paper demonstrates that an optimal local quantum thermometer, capable of precise temperature estimation, can be realized using a feasible system of spinless fermions in a 1D optical lattice, with potential experimental applications.

Contribution

It shows how to implement an optimal quantum thermometer in a realistic system of spinless fermions in the Rice-Mele model, connecting theoretical bounds with experimental measurements.

Findings

The system's sensitivity is characterized by quantum Fisher information.

Site occupation measurements can effectively estimate temperature changes.

The proposed setup achieves the fundamental lower bound for temperature estimation.

Abstract

An optimal local quantum thermometer is a quantum many-body system that saturates the fundamental lower bound for the thermal state temperature estimation accuracy [L. Correa, et. al., Phys. Rev. Lett. 114, 220405 (2015)]. Such a thermometer has a particular energy level structure with a single ground state and highly degenerated excited states manifold, with an energy gap proportional to the estimated temperature. In this work, we show that the optimal local quantum thermometer can be realized in an experimentally feasible system of spinless fermions confined in a one-dimensional optical lattice described by the Rice-Mele model. We characterize the system's sensitivity to temperature changes in terms of quantum Fisher information and the classical Fisher information obtained from experimentally available site occupation measurements.