Estimating the temperature of a cold quantum system is difficult. Usually, one measures a well-understood thermal state and uses that prior knowledge to infer its temperature. In contrast, we introduce a method of thermometry that assumes minimal knowledge of the state of a system and is potentially non-destructive. Our method uses a universal temperature-dependence of the quench dynamics of an initially thermal system coupled to a qubit probe that follows from the Tasaki-Crooks theorem for non-equilibrium work distributions. We provide examples for a cold-atom system, in which our thermometry protocol may retain accuracy and precision at subnanokelvin temperatures.
|Journal||Physical Review A: Atomic, Molecular, and Optical Physics|
|Publication status||Published - 23 May 2016|
Johnson, T. H., Cosco, F., Mitchison, M. T., Jaksch, D., & Clark, S. R. (2016). Thermometry of ultracold atoms via non-equilibrium work distributions. Physical Review A: Atomic, Molecular, and Optical Physics, 93(5). https://doi.org/10.1103/PhysRevA.93.053619, https://doi.org/10.1103/PhysRevA.93.053619