Criticality of environmental information obtainable by dynamically controlled quantum probes

ANALIA ZWICK

Bariloche, Argentina

Congreso; SLAFES XXIII Latin American Symposium on Solid State Physics; 2018

SLAFES XXIII

A universal approach to decoherence control combined with quantum estimation theory reveals a criticalbehavior, akin to a phase-transition, of the information obtainable by a qubit-probe concerning the memory timeof environmental fluctuations of a generalized Ornstein-Uhlenbeck processes. The criticality emerges only whenthe probe is subject to suitable dynamical control aimed at inferring the memory-time. A sharp transition isanticipated between two dynamical phases characterized by either a short or long memory-time compared to theprobing-time. This phase-transition of the environmental information is a fundamental feature that characterizesopen quantum-system dynamics and is important for attaining the highest estimation precision of the environmentmemory-time under experimental limitations.