共查询到20条相似文献,搜索用时 15 毫秒
1.
Song-Song Li 《International Journal of Theoretical Physics》2018,57(8):2359-2364
We investigate the entanglement dynamics in a non-Hermitian one-axis twisting Hamiltonian. Especially, we focus on the dependence of quantum entanglement on the non-Hermitian term. Its shown that the non-Hermitian term play an important role in the process of generating quantum entanglement and the more entanglement can be achieved by enhancing the non-Hermitian term. 相似文献
2.
The dynamical properties of quantum entanglement in an integrable
quantum dimer are studied in terms of the reduced-density linear entropy
with various coupling parameters and total boson numbers. The characteristic
time of decoherence process in the early-time evolution of the linear entropy
is obtained, indicating that the characteristic time and the corresponding
entropy exhibit a maximum near the position of the corresponding classical
separatrix energy. 相似文献
3.
Arun K. Pati 《Pramana》2009,73(3):485-498
Entanglement is one of the key features of quantum world that has no classical counterpart. This arises due to the linear
superposition principle and the tensor product structure of the Hilbert space when we deal with multiparticle systems. In
this paper, we will introduce the notion of entanglement for quantum systems that are governed by non-Hermitian yet PT-symmetric Hamiltonians. We will show that maximally entangled states in usual quantum theory behave like non-maximally entangled
states in PT-symmetric quantum theory. Furthermore, we will show how to create entanglement between two PT qubits using non-Hermitian Hamiltonians and discuss the entangling capability of such interaction Hamiltonians that are non-Hermitian
in nature. 相似文献
4.
Xiao San Ma 《Optics Communications》2008,281(22):5633-5638
We investigate the entanglement dynamics and decoherence of a multipartite system under an environment which can exhibit a quantum phase transition. Our result implies that the entanglement evolution depends not only on the size of the system and the quantum states of concern but also on the environment. In the sense of the linear entropy to measure decoherence induced by the environment, the decoherence-free subspaces have been identified for our model. 相似文献
5.
K. Le Hur 《Annals of Physics》2008,323(9):2208-2240
The concept of entanglement entropy appears in multiple contexts, from black hole physics to quantum information theory, where it measures the entanglement of quantum states. We investigate the entanglement entropy in a simple model, the spin-boson model, which describes a qubit (two-level system) interacting with a collection of harmonic oscillators that models the environment responsible for decoherence and dissipation. The entanglement entropy allows to make a precise unification between entanglement of the spin with its environment, decoherence, and quantum phase transitions. We derive exact analytical results which are confirmed by Numerical Renormalization Group arguments both for an ohmic and a subohmic bosonic bath. The entanglement entropy obeys universal scalings. We make comparisons with entanglement properties in the quantum Ising model and in the Dicke model. We also emphasize the possibility of measuring this entropy using charge qubits subject to electromagnetic noise; such measurements would provide an empirical proof of the existence of entanglement entropy. 相似文献
6.
Lijun Song Xiaoguang Wang Dong Yan ZhanGuo Zong 《International Journal of Theoretical Physics》2008,47(10):2635-2644
We study dynamical properties of quantum entanglement in the Dicke model with and without the rotating-wave approximation.
Specifically, we investigate the maximal entanglement and mean entanglement which reflect the underlying chaos in the system,
and a good classical-quantum correspondence is found. We also show that the maximal linear entropy can be more sensitive to
chaos than the mean linear entropy. 相似文献
7.
Considering a two-level atom interacting with the competing two-mode field, this paper investigates the entanglement between the two-level atom and the two-mode field by using the quantum reduced entropy, and that between the two-mode field by using the quantum relative entropy of entanglement. It shows that the two kinds of entanglement are dependent on the relative coupling strength of atom-field and the atomic distribution, and exhibit the periodical evolution. The maximal atom-field entanglement state can be prepared via the appropriate selection of system parameters and interaction time. 相似文献
8.
Siqiang Zhang Haitian Tang Jiajia Wei Jiaxuan Wei Irfan Ahmed Yanpeng Zhang 《Annalen der Physik》2023,535(11):2300208
Nonclassical multiphoton have attracted extensive attention to serve as entangled resources for quantum information technology. Here, the continuous-mode hyper-entangled W-class triphotons are theoretically generated through spontaneous six-wave mixing (SSWM) in 85Rb. In nonlinear optical response, Zeeman sub-states are high-dimensionally quantized by polarized dressing. High-dimensional entanglement is structured via atomic non-Hermitian nature. Through linear optical response, the temporal correlations are shaped via diverse polarized dressing. SSWM-based triphoton is a genuine triphoton possessing non-Gaussian tripartite entanglement. The high production rate is due to co-action of three strong input fields, electromagnetically induced transparency (EIT) protection, and slow light effect. Non-Hermitian nature endows the system with sensitive adjustability around exceptional points (EP). Eventually, the results demonstrate multiple SSWMs causing oscillations with multiple periods in three-photon temporal correlations for the nonlinear region, build a high-dimensional three-body entangled quantum network and transform multifarious profiles of the three-photon temporal correlations for the linear region. Especially, both high-dimensional and hyper entanglements are obtained, contributing to high quantum information capacity. Further, the system is switched among multiple states when non-Hermitian nature is manipulated by polarized dressing. The research opens a broad prospect for generating the hyper-entangled multiphoton with potential application in adjustable quantum networks of high information capacity. 相似文献
9.
10.
Pengfei Zhang 《Frontiers of Physics》2022,17(4):43201
Entanglement is one of the most important concepts in quantum physics. We review recent progress in understanding the quantum entanglement in many-body systems using large-N solvable models: the Sachdev–Ye–Kitaev (SYK) model and its generalizations. We present the study of entanglement entropy in the original SYK model using three different approaches: the exact diagonalization, the eigenstate thermalization hypothesis, and the pathintegral representation. For coupled SYK models, the entanglement entropy shows linear growth and saturation at the thermal value. The saturation is related to replica wormholes in gravity. Finally, we consider the steady-state entanglement entropy of quantum many-body systems under repeated measurements. The traditional symmetry breaking in the enlarged replica space leads to the measurement-induced entanglement phase transition. 相似文献
11.
J. S. Zhang L. Chen M. Abdel-Aty A. X. Chen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2012,66(1):2
We study the dynamics of quantum discord and entanglement of two entangled two-level
atoms within two isolated and dissipative cavities in the weak- or strong-coupling regime.
The quantum entanglement are measured by concurrence and relative entropy. The quantum
discord of two atoms based on quantum mutual information and relative entropy are also
calculated. In the weak-coupling regime, the sudden death of quantum discord and
entanglement of two atoms can occur simultaneously within a short interaction time. When
the interaction time is long, quantum discord and entanglement of two atoms could be
partially preserved due to the long-lived nature of quantum discord and entanglement.
However, in the strong-coupling regime, there is no sudden death of quantum discord though
the entanglement sudden death phenomenon occurs. In addition, we observe that entanglement
and discord will be destroyed eventually when the atom-field interactions are strong. We
also address the issue of experimental realization briefly. 相似文献
12.
We investigate the entanglement between a spin and its environment in impurity systems which exhibit a second-order quantum phase transition separating a delocalized and a localized phase for the spin. As an application, we employ the spin-boson model, describing a two-level system (spin) coupled to a sub-Ohmic bosonic bath with power-law spectral density, J(omega) proportional to omega(s) and 0 < s < 1. Combining Wilson's numerical renormalization group method and hyperscaling relations, we demonstrate that the entanglement between the spin and its environment is always enhanced at the quantum phase transition resulting in a visible cusp (maximum) in the entropy of entanglement. We formulate a correspondence between criticality and impurity entanglement entropy, and the relevance of these ideas to nanosystems is outlined. 相似文献
13.
By fully exploiting the existence of the unitarily inequivalent representations of quantum fields, we exhibit the entanglement between inner and outer particles, with respect to the event horizon of a black hole. We compute the entanglement entropy and we find that the non-unitarity of the mapping, between the vacua in the flat and the curved frames, makes the entanglement very robust. 相似文献
14.
Non-Hermitian topological edge states have many intriguing properties, however, to date, they have mainly been discussed in terms of bulk–boundary correspondence. Here, we propose using a bulk property of diffusion coefficients for probing the topological states and exploring their dynamics. The diffusion coefficient was found to show unique features with the topological phase transitions driven by parity–time (PT)-symmetric non-Hermitian discrete-time quantum walks as well as by Hermitian ones, despite the fact that artificial boundaries are not constructed by an inhomogeneous quantum walk. For a Hermitian system, a turning point and abrupt change appears in the diffusion coefficient when the system is approaching the topological phase transition, while it remains stable in the trivial topological state. For a non-Hermitian system, except for the feature associated with the topological transition, the diffusion coefficient in the PT-symmetric-broken phase demonstrates an abrupt change with a peak structure. In addition, the Shannon entropy of the quantum walk is found to exhibit a direct correlation with the diffusion coefficient. The numerical results presented herein may open up a new avenue for studying the topological state in non-Hermitian quantum walk systems. 相似文献
15.
QIU Liang WANG An-Min MA Xiao-San 《理论物理通讯》2008,49(2):516-520
We analyze the time evolution of entanglement of two-qutrit system
within the framework of Milburn's model of intrinsic decoherence.
The entanglement evolution relies not only on the parameters of
system, but also on the concrete states either pure or mixed. The
linear entropy used to measure the extent to which the
intrinsic decoherence affects quantum states is evaluated. 相似文献
16.
Rasim Dermez S. Abdel Khalek Kemal Kara Bekir Deveci G. N. Günayd?n 《Journal of Russian Laser Research》2012,33(1):42-51
Our aim is to investigate the entanglement dynamics and quantum correlations of a full-trapped ion interacting with two time-independent
laser beams in view of the Lamb–Dicke parameter. For this purpose, the three probability amplitudes in the trapped ion is
taken as ?{1