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Individual Quantum Probes for Optimal Thermometry

Luis A. Correa, Mohammad Mehboudi, Gerardo Adesso, and Anna Sanpera
Phys. Rev. Lett. 114, 220405 – Published 5 June 2015
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Abstract

The unknown temperature of a sample can be estimated with minimal disturbance by putting it in thermal contact with an individual quantum probe. If the interaction time is sufficiently long so that the probe thermalizes, the temperature can be read-out directly from its steady state. Here we prove that the optimal quantum probe, acting as a thermometer with maximal thermal sensitivity, is an effective two-level atom with a maximally degenerate excited state. When the total interaction time is insufficient to produce full thermalization, we optimize the estimation protocol by breaking it down into sequential stages of probe preparation, thermal contact, and measurement. We observe that frequently interrogated probes initialized in the ground state achieve the best performance. For both fully and partly thermalized thermometers, the sensitivity grows significantly with the number of levels, though optimization over their energy spectrum remains always crucial.

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  • Received 22 November 2014

DOI:https://doi.org/10.1103/PhysRevLett.114.220405

© 2015 American Physical Society

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Recipe for a Quantum Thermometer

Published 5 June 2015

Theorists describe the best nanoscale thermometer allowed by the laws of physics to help experimenters push the limits of technology in measurements within cells or tiny electronic circuits.

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Authors & Affiliations

Luis A. Correa1,*, Mohammad Mehboudi1, Gerardo Adesso2, and Anna Sanpera3,1

  • 1Departament de Física, Universitat Autònoma de Barcelona - E08193 Bellaterra, Spain
  • 2School of Mathematical Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
  • 3Institució Catalana de Recerca i Estudis Avançats - E08011 Barcelona, Spain

  • *LuisAlberto.Correa@uab.cat

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Issue

Vol. 114, Iss. 22 — 5 June 2015

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