paper

Fundamental limits on low-temperature quantum thermometry with finite resolution

arXiv:1711.09827 · doi:10.22331/q-2019-07-09-161

Abstract

While the ability to measure low temperatures accurately in quantum systems is important in a wide range of experiments, the possibilities and the fundamental limits of quantum thermometry are not yet fully understood theoretically. Here we develop a general approach to low-temperature quantum thermometry, taking into account restrictions arising not only from the sample but also from the measurement process. We derive a fundamental bound on the minimal uncertainty for any temperature measurement that has a finite resolution. A similar bound can be obtained from the third law of thermodynamics. Moreover, we identify a mechanism enabling sub-exponential scaling, even in the regime of finite resolution. We illustrate this effect in the case of thermometry on a fermionic tight-binding chain with access to only two lattice sites, where we find a quadratic divergence of the uncertainty. We also give illustrative examples of ideal quantum gases and a square-lattice Ising model, highlighting the role of phase transitions.

Published version. Main text: 12 pages, 5 figures; see also related work by K. Hovhannisyan and L. A. Correa at arXiv:1712.03088

References in corpus (17)

Cited by in corpus (56)