Criticality of environmental information obtainable by dynamically controlled quantum probes

ANALIA ZWICK; GONZALO A. ALVAREZ; GERSHON KURIZKI

Bariloche

Workshop; ICTP Workshop on Driven Quantum Systems; 2016

ICTP, CAB, CNEA

A universal approach to decoherence control com- bined with quantum estimation theory reveals a crit- ical behavior, akin to a phase-transition, of the in- formation obtainable by a qubit-probe concerning the memory time of environmental fluctuations of a gener- alized Ornstein-Uhlenbeck processes. The criticality emerges only when the probe is subject to suitable 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 at- taining the highest estimation precision of the environ- ment memory-time under experimental limitations.