Optimal probes for global quantum thermometry

Abstract Quantum thermodynamics has emerged as a separate sub-discipline, revising the concepts and laws of thermodynamics, at quantum scale. In particular, there been disruptive shift in way thermometry, thermometers are perceived designed. Currently, we face two major challenges thermometry. First, all existing optimally precise temperature probes local, meaning their operation is optimal only for narrow range temperatures. Second, aforesaid local mandate complex energy spectrum with immense degeneracy, rendering them impractical. Here, address these by formalizing notion global thermometry leading to development sensors over wide We observe emergence different phases such interval increased. addition, show how best approximation can be realized spin chains, implementable ion traps dots.