Geometry, robustness, and emerging unitarity in dissipation-projected dynamics

TL;DR

This paper explores how dissipation-projected dynamics in driven-dissipative quantum systems exhibit geometric properties, robustness, and can lead to emergent unitarity, revealing new insights into environment-induced quantum effects.

Contribution

It demonstrates the geometric and robust nature of dissipation-projected dynamics and shows conditions under which purely dissipative interactions can produce effective unitary evolution.

Findings

Dissipation-projected dynamics are geometric and robust.

Emergence of effective unitarity from dissipative interactions.

Identification of environment-induced quantum Zeno effect.

Abstract

Quantum information can be encoded in the set of steady-states (SSS) of a driven-dissipative system. Non steady-states are separated by a large dissipative gap that adiabatically decouples them way while the dynamics inside the SSS is governed by an effective, dissipation-projected, Hamiltonian. The latter results from a highly non-trivial interplay between a weak driving with the fast relaxation process that continuously projects the system back to the SSS. This amounts to a novel type of environment-induced quantum Zeno effect. We prove that the dissipation-projected dynamics is of geometric nature and that it is robust against different types of hamiltonian and dissipative perturbations. Remarkably, in some cases an effective unitary dynamics can emerge out of purely dissipative interactions.