Accession Number : ADA626729


Title :   Dynamical Quantum Correlations of Ising Models on an Arbitrary Lattice and Their Resilience to Decoherence


Descriptive Note : Journal article


Corporate Author : COLORADO UNIV AT BOULDER


Personal Author(s) : Foss-Feig, Michael ; Hazzard, Kaden R ; Bollinger, John J ; Rey, Ana M ; Clark, Charles W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a626729.pdf


Report Date : Jan 2013


Pagination or Media Count : 37


Abstract : Ising models, and the physical systems described by them, play a central role in generating entangled states for use in quantum metrology and quantum information. In particular, ultracold atomic gases, trapped ion systems, and Rydberg atoms realize long-ranged Ising models, which even in the absence of a transverse field can give rise to highly non-classical dynamics and long-range quantum correlations. In the first part of this paper, we present a detailed theoretical framework for studying the dynamics of such systems driven (at time t = 0) into arbitrary unentangled non-equilibrium states, thus greatly extending and unifying the work of Ref. [1]. Specifically, we derive exact expressions for closed-timepath ordered correlation functions, and use these to study experimentally relevant observables, e.g. Bloch vector and spin-squeezing dynamics. In the second part, these correlation functions are then used to derive closed-form expressions for the dynamics of arbitrary spin-spin correlation functions in the presence of both T1 (spontaneous spin relaxation/excitation) and T2 (dephasing) type decoherence processes. Even though the decoherence is local, our solution reveals that the competition between Ising dynamics and T1 decoherence gives rise to an emergent non-local dephasing effect, thereby drastically amplifying the degradation of quantum correlations. In addition to identifying the mechanism of this deleterious effect, our solution points toward a scheme to eliminate it via measurement-based coherent feedback.


Descriptors :   *ATOMS , *IONS , *QUANTUM THEORY , AMPLIFICATION , CORRELATION , DEGRADATION , DYNAMICS , EXCITATION , FERROMAGNETIC MATERIALS , FUNCTIONS(MATHEMATICS) , GASES , METROLOGY , MODELS , NONEQUILIBRIUM FLOW , OBSERVATION , PHYSICAL PROPERTIES , RELAXATION , RESILIENCE , RYDBERG CONSTANT , SOLUTIONS(GENERAL) , SPIN STATES , SPINNING(MOTION) , TRANSVERSE , TRAPPING(CHARGED PARTICLES) , VECTOR ANALYSIS


Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Quantum Theory and Relativity


Distribution Statement : APPROVED FOR PUBLIC RELEASE