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1.
Recently Seevinck and Uffink argued that genuine multipartite entanglement (GME) had not been established in the experiments designed to confirm GME. In this paper, we use the Bell-type inequalities introduced by Seevinck and Svetlichny [M. Seevinck, G. Svetlichny, Phys. Rev. Lett. 89 (2002) 060401] to investigate the GME problem in the one-dimensional transverse-field Ising model. We show explicitly that the ground states of this model violate the inequality when the external transverse magnetic field is weak, which indicate that the ground states in this model with weak magnetic field are fully entangled. Since this model can be simulated with nuclear magnetic resonance, our results provide a fresh approach to experimental test of GME. 相似文献
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The interplay between disorder, quantum fluctuations, and dissipation is studied in the random transverse Ising chain coupled to a dissipative Ohmic bath with a real space renormalization group. A typically very large length scale L* is identified above which the physics of frozen clusters dominates. Below L* a strong-disorder fixed point determines scaling at a pseudocritical point. In a Griffiths-McCoy region frozen clusters produce already a finite magnetization resulting in a classical low temperature behavior of the susceptibility and specific heat. These override the confluent singularities that are characterized by a continuously varying exponent z and are visible above a temperature T*approximately L*-z. 相似文献
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A random, quantum model of interacting spins, where the spin operators are represented by bilinear combinations of fermions, is studied in the Ising limit and in the static approximation. Assuming replica symmetry we recover basically the results of Sherrington and Kirkpatrick. Effects of quantum fluctuations remain in the determination of the static susceptibility χ as an independent order parameter and the breakdown of the Fischer relation. 相似文献
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Geoffrey R. Grimmett Tobias J. Osborne Petra F. Scudo 《Journal of statistical physics》2008,131(2):305-339
We study the asymptotic scaling of the entanglement of a block of spins for the ground state of the one-dimensional quantum
Ising model with transverse field. When the field is sufficiently strong, the entanglement grows at most logarithmically in
the number of spins. The proof utilises a transformation to a model of classical probability called the continuum random-cluster
model, and is based on a property of the latter model termed ratio weak-mixing. In an intermediate result, we establish an
exponentially decaying bound on the operator norm of differences of the reduced density operator. Of special interest is the
mathematical rigour of this work, and the fact that the proof applies equally to a large class of disordered interactions. 相似文献
7.
Using the measure of interference defined in this paper, we investigate the quantum phase transition of one-dimensional Ising chains. We find that thermal fluctuations affect the interference more strongly at the critical point. We also show that the derivative of the interference with respect to the coupling parameter, A, can be depressed by the thermal fluctuation. Finally, we find that this suppression is due to multi-particle excitations. 相似文献
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We study the quantum phases of anisotropic XY spin chain in presence and absence of adiabatic quench. A connection between geometric phase and criticality is established from the dynamical behavior of the geometric phase for a quench induced quantum phase transition in a quantum spin chain. We predict XX criticality associated with a sequence of non-contractible geometric phases. 相似文献
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We analyze a 1D Ising system with anomalous distributions of nearest neighbor interactions and show that the single-spin-flip dynamics exhibit breakdown of dynamic scaling. The results are obtained by a real-space numerical method applied to the exact equations of motion and they may be explained by domain wall motion arguments reformulated in terms of extreme value statistics. 相似文献
10.
Jakob E. Björnberg 《Communications in Mathematical Physics》2015,337(2):879-907
Adapting the recent argument of Aizenman, Duminil-Copin and Sidoravicius for the classical Ising model, it is shown here that the magnetization in the transverse-field Ising model vanishes at the critical point. The proof applies to the ground state in dimension d ≥ 2 and to positive-temperature states in dimension d ≥ 3, and relies on graphical representations as well as an infrared bound. 相似文献
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Grimmett Geoffrey R. Osborne Tobias J. Scudo Petra F. 《Journal of statistical physics》2020,178(1):281-296
Journal of Statistical Physics - A rigorous proof is presented of the boundedness of the entanglement entropy of a block of spins for the ground state of the one-dimensional quantum Ising model... 相似文献
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We study the time dependence of the magnetization profile, m(l)(t), of a large finite open quantum Ising chain after a quench. We observe a cyclic variation, in which starting with an exponentially decreasing period the local magnetization arrives to a quasistationary regime, which is followed by an exponentially fast reconstruction period. The nonthermal behavior observed at near-surface sites turns over to thermal behavior for bulk sites. In addition to the standard time and length scales a nonstandard time scale is identified in the reconstruction period. 相似文献
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An elastic Ising model for a one-dimensional diatomic spin chain is proposed to explain the ferroelectricity induced by the collinear magnetic order with a low-excited energy state. A statistical theory based on this model is developed to calculate the electrical and magnetic properties of Ca3CoMnO6, a typical quasi-one-dimensional diatomic spin chain system. The calculated ferroelectric polarization and dielectric susceptibility show a good agreement with recently reported data on Ca3Co2-xMnxO6 (x ≈0.96) (Phys. Rev. Lett. 100 047601 (2008)), although the predicted magnetic susceptibility does not coincide well with experiment. We also address the rationality and deficiency of this model by including a first-order correction which improves the consistency between the model and experiment. 相似文献
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An elastic Ising model for a one-dimensional diatomic spin chain is
proposed to explain the ferroelectricity induced by the collinear
magnetic order with a low-excited energy state. A statistical theory
based on this model is developed to calculate the electrical and
magnetic properties of Ca3CoMnO6, a typical
quasi-one-dimensional diatomic spin chain system. The calculated
ferroelectric polarization and dielectric susceptibility show a good
agreement with recently reported data on Ca3Co2-xMnxO6 (x ≈0.96) (Phys. Rev. Lett. 100 047601 (2008)), although the predicted magnetic susceptibility
does not coincide well with experiment. We also address the
rationality and deficiency of this model by including a first-order
correction which improves the consistency between the model and
experiment. 相似文献
15.
Silevitch DM Gannarelli CM Fisher AJ Aeppli G Rosenbaum TF 《Physical review letters》2007,99(5):057203
A transverse magnetic field is used to scan the diagonal and off-diagonal susceptibility of the uniaxial quantum magnet, LiHo(0.045) Y(0.955)F(4). Clusters of strongly coupled spins act as the primary source for the response functions, which result from a field-induced quantum projection of the system into a classically forbidden (meaning non-Ising) regime. Calculations based on spin pairs reproduce only some features of the data and fail to predict the measured off-diagonal response, providing evidence of a multispin collective state. 相似文献
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A sequence space model which describes the interplay of mutation and selection in molecular evolution is shown to be equivalent to an Ising quantum chain. Observable quantities tailored to match the biological situation are then employed to treat three fitness landscapes exactly. 相似文献
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The Gibbs states of binary lattice systems can be characterized by their stability with respect to certain microscopic transitions which have a simple physical interpretation. A detailed analysis is provided for the case of a one-dimensional lattice gas with nearest-neighbor interactions. 相似文献
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The elements of the tensor of the susceptibility and the staggered susceptibility of a one-dimensional I Ising chain, with xx couplings between the spins are investigated in the presence of a magnetic field b parallel with or perpendicular to the x direction. Exact expressions are given for all susceptibilities, apart from the parallel susceptibilities in a transverse field which are evaluated by perturbation calculation. Special attention is paid to the conditions under which a susceptibility can have a minimum for b = 0. Furthermore, a system with weakly coupled Ising chains is considered on the basis of a model hamiltonian with separable interchain interactions. 相似文献
20.
Ricardo L. Silva 《Solid State Communications》2005,134(5):313-317
We study static vacancies on a ferromagnetic spin-1/2 chain described by the transverse Ising model with second neighbor interactions at zero temperature. Using exact diagonalization techniques and applying a finite-size scaling approach, it is found that a strong magnetic field induces an effective potential of interaction between two vacancies that is attractive. 相似文献