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[hal-01774154] Out-of-time-ordered measurements as a probe of quantum dynamics  (24/04/18)  
Probing the out-of-equilibrium dynamics of quantum matter has gained renewed interest owing to immense experimental progress in artificial quantum systems. Dynamical quantum measures such as the growth of entanglement entropy and out-of-time-ordered correlators (OTOCs) have been shown to provide great insight by exposing subtle quantum features invisible to traditional measures such as mass transport. However, measuring them in experiments requires either identical copies of the system, an ancilla qubit coupled to the whole system, or many measurements on a single copy, thereby making scalability extremely complex and hence, severely limiting their potential. Here, we introduce an alternative quantity, the out-of-time-ordered measurement (OTOM), which involves measuring a single observable on a single copy of the system, while retaining the distinctive features of the OTOCs. We show, theoretically, that OTOMs are closely related to OTOCs in a doubled system with the same quantum statistical properties as the original system. Using exact diagonalization, we numerically simulate classical mass transport, as well as quantum dynamics through computations of the OTOC, the OTOM, and the entanglement entropy in quantum spin chain models in various interesting regimes (including chaotic and many-body localized systems). Our results demonstrate that an OTOM can successfully reveal subtle aspects of quantum dynamics hidden to classical measures and, crucially, provide experimental access to them.

[tel-01760790] Etude d'états exotiques corrélés de la matière en basse dimension  (23/04/18)  
[hal-01757283] Identifying Two-Dimensional Z2 Antiferromagnetic Topological Insulators  (04/04/18)  
[hal-01757260] Persistence of the gapless spin liquid in the breathing kagome Heisenberg antiferromagnet  (04/04/18)  
[hal-01703570] Competing orders in the Hofstadter t–J model  (08/02/18)  
[hal-01692501] Observation of Slow Dynamics near the Many-Body Localization Transition in One-Dimensional Quasiperiodic Systems  (26/01/18)  
[hal-01691955] Nearly Deconfined Spinon Excitations in the Square-Lattice Spin-1/2 Heisenberg Antiferromagnet  (25/01/18)  
[hal-01657695] Weak- versus strong-disorder superfluid—Bose glass transition in one dimension  (11/01/18)  
[hal-01641986] Vanishing Cycles and Cartan Eigenvectors  (28/02/18)  
[hal-01618835] Investigation of the chiral antiferromagnetic Heisenberg model using PEPS  (11/01/18)  
[hal-01618813] Entanglement properties of the two-dimensional SU(3) Affleck-Kennedy-Lieb-Tasaki state  (11/01/18)  
[hal-01587596] Quantum critical phase with infinite projected entangled paired states  (11/01/18)  
[hal-01529950] Spin-1/2 kagome XXZ model in a field: Competition between lattice nematic and solid orders  (11/01/18)  
[hal-01522773] Z2 antiferromagnetic topological insulators with broken C4 symmetry  (11/01/18)  
[hal-01513074] Local injection of pure spin current generates electric current vortices  (11/01/18)  


Mots clés

Optical lattices Modèle de Heisenberg de spin 1/2 Antiferromagnetism Magnétisme quantique Strongly Correlated Electrons Electronic correlations Variational Monte Carlo Cristaux electroniques Électrons fortement corrélés Modèle de Heisenberg Variational quantum Monte Carlo U1 Dirac spin liquid Faible dimension High-Tc Anyons Criticality Fermions fortement correles Superconductivity Luttinger liquids Dimers Méthodes numériques Antiferromagnetic conductors Frustrated systems Magnetization plateau Gutzwiller projected fermionic variational wave functions Modèle effectif Courbe d'aimantation Disorder Bosons de coeur dur Magnetic-breakdown Magnetisme quantique Hard-core bosons Fidélité et transitions de phases quantiques Quantum magnetism Fermions Valence bond crystals Lanczos method Plateau d'aimantation Monte-Carlo quantique Crticalite Heisenberg model Magnetisme Hamiltonien effectif Correlations electroniques Kagome lattice Spin liquids Criticalite Magnetic field Dirac spin liquid Mott insulator Low dimension Modèles de dimères quantiques généralisés Kagomé lattice Supraconductivité Effective model Corrélées Ladders Frustration Fidelity approach to quantum phase transitions Physique de la matière condensée Quantum dimer models t-J model superconductivity magnetism Generalized quantum dimer models Bose glass Magnetization plateaux Gutzwiller projected wave functions Modele effectif Fidelity susceptibility Orbital magnetism Dimeres Hubbard Isolant de Mott Magnetic quantum oscillations Correlated Heisenberg antiferromagnet Numerical methods Plateaux d'aimantation Heisenberg Model Effective hamiltonian Chaines de spin Frustrated magnetism Layered organic metals Condensed matter physics Green function Monte Carlo Frustrated lattices Désordre Kagome Interactions T-J model Green's function Monte Carlo Magnetization curve Low dimensions Basse dimension Monte Carlo quantique Condensed Matter Quantum information Lanczos Champ magnétique Magnetisation plateaux Quantum dimer models t-J model Low-dimensional systems