Global and local thermometry schemes in coupled quantum systems. (3rd October 2017)

• Record Type: Journal Article
• Authors: Campbell, Steve; Mehboudi, Mohammad; Chiara, Gabriele De; Paternostro, Mauro
• Is Part Of: New journal of physics. Volume 19:Number 10(2017:Oct.)
• Publication Date: 2017-10-03
• Subjects: thermometry -- Bose–Hubbard model -- quantum estimation theory -- quantum thermodynamics; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/aa7fac
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We study the ultimate bounds on the estimation of temperature for an interacting quantum system. We consider two coupled bosonic modes that are assumed to be thermal and using quantum estimation theory establish the role the Hamiltonian parameters play in thermometry. We show that in the case of a conserved particle number the interaction between the modes leads to a decrease in the overall sensitivity to temperature, while interestingly, if particle exchange is allowed with the thermal bath the converse is true. We explain this dichotomy by examining the energy spectra. Finally, we devise experimentally implementable thermometry schemes that rely only on locally accessible information from the total system, showing that almost Heisenberg limited precision can still be achieved, and we address the (im)possibility for multiparameter estimation in the system.