Criticality of environmental information obtainable by dynamically controlled quan- tum probes

ANALIA ZWICK; GONZALO A. ALVAREZ; GERSHON KURIZKI

Simposio; XXIII Latin American Symposium on Solid State Physics; 2018

A universal approach to decoherence control com- bined with quantum estimation theory reveals a cri- tical behavior, akin to a phase-transition, of the in- formation obtainable by a qubit-probe concerning the memory time of environmental fluctuations of a ge- neralized Ornstein-Uhlenbeck processes. The critica- lity emerges only when the probe is subject to suita- ble dynamical control aimed at inferring the memory- time. A sharp transition is anticipated between two dynamical phases characterized by either a short or long memory-time compared to the probing-time. This phase-transition of the environmental informa- tion is a fundamental feature that characterizes open quantum-system dynamics and is important for attai- ning the highest estimation precision of the environ- ment memory-time under experimental limitations