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Patrick Potts

Postdoctoral fellow

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Tight bound on finite-resolution quantum thermometry at low temperatures

Author

  • Mathias R. Jørgensen
  • Patrick P. Potts
  • Matteo G. A. Paris
  • Jonatan B. Brask

Summary, in English

Precise thermometry is of wide importance in science and technology in general and in quantum systems in particular. Here, we investigate fundamental precision limits for thermometry on cold quantum systems, taking into account constraints due to finite measurement resolution. We derive a tight bound on the optimal precision scaling with temperature, as the temperature approaches zero. The bound demonstrates that under finite resolution, the variance in any temperature estimate must decrease slower than linearly. This scaling can be saturated by monitoring the nonequilibrium dynamics of a single-qubit probe. We support this finding by numerical simulations of a spin-boson model. In particular, this shows that thermometry with a vanishing absolute error at low temperature is possible with finite resolution, answering an interesting question left open by previous work. Our results are relevant both fundamentally, as they illuminate the ultimate limits to quantum thermometry, and practically, in guiding the development of sensitive thermometric techniques applicable at ultracold temperatures.

Department/s

  • Mathematical Physics
  • NanoLund

Publishing year

2020

Language

English

Publication/Series

Physical Review Research

Volume

2

Issue

3

Document type

Journal article

Publisher

American Physical Society

Topic

  • Other Physics Topics

Status

Published

ISBN/ISSN/Other

  • ISSN: 2643-1564