TY - JOUR

T1 - Collective dynamics of multimode bosonic systems induced by weak quantum measurement

AU - Mazzucchi, Gabriel

AU - Kozlowski, Wojciech

AU - Caballero-Benitez, Santiago F.

AU - Mekhov, Igor B.

N1 - Funding Information: The work was supported by the EPSRC (DTA and EP/I004394/1). Publisher Copyright: © 2016 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 2016/7

Y1 - 2016/7

N2 - In contrast to the fully projective limit of strong quantum measurement, where the evolution is locked to a small subspace (quantum Zeno dynamics), or even frozen completely (quantum Zeno effect), the weak non-projective measurement can effectively compete with standard unitary dynamics leading to nontrivial effects. Here we consider global weak measurement addressing collective variables, thus preserving quantum superpositions due to the lack of which path information. While for certainty we focus on ultracold atoms, the idea can be generalized to other multimode quantum systems, including various quantum emitters, optomechanical arrays, and purely photonic systems with multiple-path interferometers (photonic circuits). We show that light scattering from ultracold bosons in optical lattices can be used for defining macroscopically occupied spatial modes that exhibit long-range coherent dynamics. Even if the measurement strength remains constant, the quantum measurement backaction acts on the atomic ensemble quasi-periodically and induces collective oscillatory dynamics of all the atoms. We introduce an effective model for the evolution of the spatial modes and present an analytic solution showing that the quantum jumps drive the system away from its stable point. We confirm our finding describing the atomic observables in terms of stochastic differential equations.

AB - In contrast to the fully projective limit of strong quantum measurement, where the evolution is locked to a small subspace (quantum Zeno dynamics), or even frozen completely (quantum Zeno effect), the weak non-projective measurement can effectively compete with standard unitary dynamics leading to nontrivial effects. Here we consider global weak measurement addressing collective variables, thus preserving quantum superpositions due to the lack of which path information. While for certainty we focus on ultracold atoms, the idea can be generalized to other multimode quantum systems, including various quantum emitters, optomechanical arrays, and purely photonic systems with multiple-path interferometers (photonic circuits). We show that light scattering from ultracold bosons in optical lattices can be used for defining macroscopically occupied spatial modes that exhibit long-range coherent dynamics. Even if the measurement strength remains constant, the quantum measurement backaction acts on the atomic ensemble quasi-periodically and induces collective oscillatory dynamics of all the atoms. We introduce an effective model for the evolution of the spatial modes and present an analytic solution showing that the quantum jumps drive the system away from its stable point. We confirm our finding describing the atomic observables in terms of stochastic differential equations.

KW - BoseEinstein condensate

KW - conditional dynamics quantum jumps

KW - light interaction with matter

KW - quantum measurement

KW - ultracold gases

UR - http://www.scopus.com/inward/record.url?scp=84979255904&partnerID=8YFLogxK

U2 - 10.1088/1367-2630/18/7/073017

DO - 10.1088/1367-2630/18/7/073017

M3 - Article

AN - SCOPUS:84979255904

VL - 18

JO - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

IS - 7

M1 - 073017

ER -