8 papers · 1 filter
Surpassing thermal-state limit in thermometry via non-completely positive quantum encoding
Anindita Sarkar, Paranjoy Chaki, Debarupa Saha +1
Conventional quantum thermometry assumes completely positive (CP) encoding maps, where the probe is initially uncorrelated with the environment. We consider realistic scenarios wit…
Dynamical Quantum Phase Transitions in Boundary Time Crystals
Sukrut Mondkar, Priya Ghosh, Ujjwal Sen
We demonstrate the existence of a dynamical quantum phase transition (DQPT) in a dissipative collective-spin model that exhibits the boundary time crystal (BTC) phase. We initializ…
Role reversal in quantum Mpemba effect
Arunabha Das, Paranjoy Chaki, Priya Ghosh +1
We investigate the quantum Mpemba effect in a dissipative Dicke model, which consists of a spin-1/2 ensemble coupled to a bosonic mode, which in turn is coupled to a bosonic bath.…
Comparing physical quantities with finite-precision: beyond standard metrology and an illustration for cooling in quantum processes
Anindita Sarkar, Paranjoy Chaki, Priya Ghosh +1
We propose a general framework to compare the values of a physical quantity pertaining to two - or more - physical setups, in the finite-precision scenario. Such a situation requir…
Optimal quantum precision in noise estimation: Is entanglement necessary?
Shuva Mondal, Priya Ghosh, Ujjwal Sen
We ask whether the optimal probe is entangled, and if so, what is its character and amount, for estimating the noise parameter of a large class of local quantum encoding processes…
Role of phase of optimal probe in noncommutativity vs coherence in quantum multiparameter estimation
Ritopriyo Pal, Priya Ghosh, Ahana Ghoshal +1
Quantum multiparameter estimation offers a framework for the simultaneous estimation of multiple parameters, pertaining to possibly noncommutating observables. While the optimal pr…