Quantum thermometry in electromagnetic field of cosmic string spacetime

A scheme for enhancing the quantum Fisher information of quantum thermometry is proposed where the detector used to explore the thermal bath in cosmic string spacetime is a two-level atom which is coupled to electromagnetic fields. By deriving its dynamical evolution via the method of open quantum system, our scheme indicates the quantum Fisher information of temperature depends on the deficit angle, evolution time, detector initial state, polarization direction, the temperature itself and its position. Our results show the quantum Fisher information can finally be maximized by the estimation of local measurements, and therefore, the precision of estimation can be improved.