Decoherence of a quantum system coupled to an XY spin chain: Role of the initial state of the spin chain

Quantum correlations (including entanglement and quantum discord) of two qubits symmetrically coupled to the surrounding XY spin chain in the presence of a transverse magnetic field are studied. We investigate the dynamic evolution of the quantum correlations of the two qubits when the surrounding spin chain is in the thermal equilibrium state. Numerical results show that the thermal effects can accelerate the decay process of the quantum correlations if the initial state of the composite system is not in the decoherence free space. When the temperature is high enough, the quantum phase transition driven by the external magnetic field completely disappear.

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Loschmidt Echo of a central spin coupled to an XY spin chain: The role of the Dzyaloshinsky-Moriya interaction

Chinese Physics C ◽

10.1088/1674-1137/38/7/074102 ◽

2014 ◽

Vol 38 (7) ◽

pp. 074102

Author(s):

Han-Li Lian

Keyword(s):

Spin Chain ◽

Xy Spin Chain ◽

Loschmidt Echo ◽

Moriya Interaction

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Loschmidt echo of a central spin coupled to an XY spin chain: Role of three-site interaction

Physica B Condensed Matter ◽

10.1016/j.physb.2011.08.048 ◽

2011 ◽

Vol 406 (22) ◽

pp. 4278-4282 ◽

Cited By ~ 2

Author(s):

HanLi Lian

Keyword(s):

Spin Chain ◽

Xy Spin Chain ◽

Loschmidt Echo

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BERRY PHASE AND CRITICAL BEHAVIOR OF THE XY SPIN CHAIN WITH THREE-SITE INTERACTION

Modern Physics Letters B ◽

10.1142/s0217984912501412 ◽

2012 ◽

Vol 26 (22) ◽

pp. 1250141 ◽

Cited By ~ 2

Author(s):

HANLI LIAN

Keyword(s):

Spin Chain ◽

Berry Phase ◽

Finite Size ◽

Transverse Magnetic ◽

Anomalous Behavior ◽

Quantum Criticality ◽

Critical Properties ◽

Finite Size Scaling ◽

Surrounding Environment ◽

Xy Spin Chain

By calculating the Berry Phase (BP) of a central spin, the quantum criticality of the surrounding environment described by an XY spin chain with the three-site interaction in a transverse magnetic field is explored. The BP presents anomalous behavior along the critical region. The finite-size scaling behaviors suggest that the BP of the central spin can well capture the critical properties of the XY spin chain with the three-site interaction.

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Theoretical study of Zeno and anti-Zeno effects on photodissociation dynamics: A model approach

Journal of Theoretical and Computational Chemistry ◽

10.1142/s021963361650070x ◽

2016 ◽

Vol 15 (08) ◽

pp. 1650070 ◽

Cited By ~ 2

Author(s):

Bikram Nath ◽

Chandan Kumar Mondal

Keyword(s):

Repeated Measurements ◽

Time Interval ◽

Mathematical Tool ◽

Population Transfer ◽

Vibrational States ◽

Initial State ◽

Zeno Effect ◽

Dissociation Dynamics ◽

Vibrational Population

Zeno and anti-Zeno effects in the evolution of the multi-photonic dissociation dynamics of the diatomic molecule HBr[Formula: see text] owing to repeated measurements demand if the system in the initial state have been studied. The effects have been calculated numerically for the case of vibrational population transfer and dissociation dynamics of HBr[Formula: see text] taking it as a model. We use time-dependent Fourier grid Hamiltonian (TDFGH) method as a mathematical tool in presence of intense radiation field as perturbation. The effects have been explored through a probable mechanism of population transfer from the ground vibrational state to the different upper vibrational states which ultimately go to the dissociation continuum. The results show significant differences in the mechanism of population transfer and the significant role of time interval of measurement ([Formula: see text] in Zeno and anti-Zeno effects. In case of survival probability of ground vibrational states, there is Zeno effect when the frequency of the laser to which the molecule is submitted is near the vibrational [Formula: see text] to [Formula: see text] resonance, while there is anti-Zeno effect if it is far from this resonance.

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Quantum-Heat Fluctuation Relations in Three-Level Systems Under Projective Measurements

Condensed Matter ◽

10.3390/condmat5010017 ◽

2020 ◽

Vol 5 (1) ◽

pp. 17 ◽

Cited By ~ 1

Author(s):

Guido Giachetti ◽

Stefano Gherardini ◽

Andrea Trombettoni ◽

Stefano Ruffo

Keyword(s):

Energy Scale ◽

Quantum Measurements ◽

Thermal Component ◽

Initial State ◽

Fluctuation Relations ◽

N Level ◽

Two Level Systems ◽

Jarzynski Equality ◽

Projective Measurements

We study the statistics of energy fluctuations in a three-level quantum system subject to a sequence of projective quantum measurements. We check that, as expected, the quantum Jarzynski equality holds provided that the initial state is thermal. The latter condition is trivially satisfied for two-level systems, while this is generally no longer true for N-level systems, with N > 2 . Focusing on three-level systems, we discuss the occurrence of a unique energy scale factor β eff that formally plays the role of an effective inverse temperature in the Jarzynski equality. To this aim, we introduce a suitable parametrization of the initial state in terms of a thermal and a non-thermal component. We determine the value of β eff for a large number of measurements and study its dependence on the initial state. Our predictions could be checked experimentally in quantum optics.

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Modeling an Explosive Liquid Outflow from High Pressure Thin Tubes and Nozzles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.851.377 ◽

2016 ◽

Vol 851 ◽

pp. 377-382

Author(s):

Raisa Bolotnova ◽

Andrey Topolnikov ◽

Valeria Korobchinskaya

Keyword(s):

Liquid Mixture ◽

Saturation Temperature ◽

Cylindrical Tube ◽

Opening Angle ◽

Radial Expansion ◽

Two Dimensional ◽

Initial State ◽

Parabolic Form ◽

Conical Form

To describe the explosive flow in thin tubes the model of vapor-liquid mixture with heat and mass transfer in two-dimensional axisymmetric formulation is employed. The phase transformation is significantly amplified with increasing of initial saturation temperature. The radial expansion of the jet outflow occurs due to the intensification of vaporization from cylindrical to conical form and parabolic form for supercritical initial state. Another problem applied to the outflow of a detonation wave in liquid filled with chemically active gas bubbles from the thin cylindrical tube. Modeling shows the important role of the opening angle of the outflow jet, which can either support the detonation or put it down.

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