Critical quantum thermometry and its feasibility in spin systems

In this work, we study temperature sensing with finite-sized strongly correlated systems exhibiting quantum phase transitions. We use the Fisher information (QFI) approach to quantify sensitivity in estimation, and apply a finite-size scaling framework link critical exponents of system around points. numerically calculate QFI points for two experimentally-realizable systems: spin-1 Bose-Einstein condensate spin-chain Heisenberg XX model presence an external magnetic field. Our results confirm properties QFI. Furthermore, discuss experimentally-accessible observables that (nearly) saturate at these systems.