Precision thermometry and the quantum speed limit. (5th February 2018)

• Record Type: Journal Article
• Authors: Campbell, Steve; Genoni, Marco G; Deffner, Sebastian
• Is Part Of: Quantum science and technology. Volume 3:Number 2(2018)
• Publication Date: 2018-02-05
• Subjects: thermometry -- quantum speed limits -- energy–time uncertainty principle -- quantum metrology; Quantum theory -- Periodicals; Quantum theory; Periodicals; 530
• DOI: 10.1088/2058-9565/aaa641
• Languages: English
• ISSNs: 2058-9565

Abstract

Abstract: We assess precision thermometry for an arbitrary single quantum system. For a d -dimensional harmonic system we show that the gap sets a single temperature that can be optimally estimated. Furthermore, we establish a simple linear relationship between the gap and this temperature, and show that the precision exhibits a quadratic relationship. We extend our analysis to explore systems with arbitrary spectra, showing that exploiting anharmonicity and degeneracy can greatly enhance the precision of thermometry. Finally, we critically assess the dynamical features of two thermometry protocols for a two level system. By calculating the quantum speed limit we find that, despite the gap fixing a preferred temperature to probe, there is no evidence of this emerging in the dynamical features.