Exploiting nonequilibrium phase transitions and strong symmetries for continuous measurement of collective observables

Abstract

Dissipative many-body quantum dynamics can feature strong symmetries which give rise to conserved quantities. We discuss here how a strong symmetry in conjunction with a nonequilibrium phase transition allows to devise a protocol for measuring collective many-body observables. To demonstrate this idea we consider a collective spin system whose constituents are governed by a dissipative dynamics that conserves the total angular momentum. We show that by continuously monitoring the system output the value of the total angular momentum can be inferred directly from the time-integrated emission signal, without the need of repeated projective measurements or reinitializations of the spins. This may offer a route towards the measurement of collective properties in qubit ensembles, with applications in quantum tomography, quantum computation and quantum metrology.

References in corpus (19)

• QuTiP 2: A Python framework for the dynamics of open quantum systems
• A note on symmetry reductions of the Lindblad equation: transport in constrained open spin chains
• Dissipative Phase Transition in Central Spin Systems
• Dynamical phase transition in the open Dicke model
• Dynamical Phase Transitions and Instabilities in Open Atomic Many-Body Systems
• Observation of a dissipative phase transition in a one-dimensional circuit QED lattice
• Detecting multiparticle entanglement of Dicke states
• Enhanced metrology at the critical point of a many-body Rydberg atomic system
• Critical dynamical properties of a first-order dissipative phase transition
• Signatures of a dissipative phase transition in photon correlation measurements
• Dissipative Phase Transition in the Open Quantum Rabi Model
• Bayesian parameter inference from continuously monitored quantum systems
• Heating-Induced Long-Range $\eta$-Pairing in the Hubbard Model
• Characterization of dynamical phase transitions in quantum jump trajectories beyond the properties of the stationary state
• Collective processes of an ensemble of spin-1/2 particles
• Ultimate limits for quantum magnetometry via time-continuous measurements
• Metastability in an open quantum Ising model
• Parameter estimation and system identification for continuously-observed quantum systems
• Quantum frequency estimation with conditional states of continuously monitored independent dephasing channels

Cited by in corpus (3)

• Designing open quantum systems for enabling quantum enhanced sensing through classical measurements
• Quantum metrology through spectral measurements in quantum optics
• Revealing emergent many-body phenomena by analyzing large-scale space-time records of monitored quantum systems