Alberto Biella
(CNR-INO)

Abstract: In this talk I will discuss the stochastic dynamics of two qubits subject to one- and two-site correlated continuous weak measurements ^[1]. When measurements dominates over the local unitary evolution the system’s dynamics is constrained and part of the physical Hilbert space becomes inaccessible: a typical signature of the Quantum Zeno (QZ) effect. The competition between these two measurement processes give rise to two distinct QZ regimes, we dubbed standard and correlated, characterised by a different topology of the allowed region of the physical Hilbert space being a simply and non-simply connected domain, respectively. The transition between these two phases and an ergodic region where the entirety of the Hilbert space is accessible is discontinuous and is reflected on the structure of classical two-site correlation function. We develop a theory based a stochastic Gutzwiller ansatz for the wavefunction which is able to capture the structure of the phase diagram. Finally we show how the two QZ regimes are intimately connected to the topology of the flow of the underlying non-Hermitian Hamiltonian governing the no-click evolution.

Zoom registration link:

https://zoom.us/meeting/register/a-CfcStpQiinslqMpXKVLQ