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

被引：0

作者：

Cabot, Albert ^{[1
]}

Carollo, Federico ^{[2
]}

Lesanovsky, Igor ^{[1
,3
,4
]}

机构：

[1] Eberhard Karls Univ Tubingen, Inst Theoret Phys, Morgenstelle 14, D-72076 Tubingen, Germany

[2] Coventry Univ, Ctr Fluid & Complex Syst, Coventry CV1 2TT, England

[3] Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England

[4] Univ Nottingham, Ctr Math & Theoret Phys Quantum Nonequilibrium Sys, Nottingham NG7 2RD, England

来源：

PHYSICAL REVIEW A | 2024年 / 110卷 / 06期

基金：

欧盟地平线“2020”;

关键词：

!text type='PYTHON']PYTHON[!/text] FRAMEWORK; DYNAMICS; QUTIP;

D O I：

10.1103/PhysRevA.110.L060601

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

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.

引用

页数：7