Entanglement dephasing dynamics driven by a bath of spins

Xu, Jie; Jing, Jun; Yu, Ting

doi:10.1088/1751-8113/44/18/185304

Cited by 10 publications

(4 citation statements)

References 43 publications

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“…This model was significant for the central spins would hold coherence in a comparatively long time [36][37][38] under a spin environment. It constitutes an important platform to investigate the entanglement dynamics [39][40][41] and the quantum control strategy [42]. In this spin-charger protocol, it is interesting to find a trade-off between the maximum stored energy and the optimal average charging power by tuning the charger size and the collective advantage represented by the superior power-law scaling with respect to the battery size.…”

Section: Introductionmentioning

confidence: 99%

High-capacity and high-power collective charging with spin chargers

Huangfu,

Jing

2021

Preprint

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Quantum battery works as a micro-or nano-device to store and redistribute energy at the quantum level. Here we propose a spin-charger protocol, in which the battery cells are charged by a finite number of spins through a general Heisenberg XY interaction. Under the isotropic interaction, the spin-charger protocol is endowed with a higher capacity in terms of the maximum stored energy than the conventional protocols, where the battery is charged by a continuous-variable system, e.g., a cavity mode. By tuning the charger size, a trade-off between the maximum stored energy and the average charging power is found in comparison to the cavity-charger protocol in the Tavis-Cummings model. Quantum advantage of our protocol is manifested by the scaling behavior of the optimal average power with respect to the battery size, in comparing the collective charging scheme to its parallel counterpart. We also discuss the detrimental effect on the charging performance from the anisotropic interaction between the battery and the charger, the non-ideal initial states for both of them, and the crosstalk among the charger spins. A strong charger-charger interaction can be used to decouple the battery and the charger. Our findings about the advantages of the spin-charger protocol over the conventional cavity-charger protocols, including the high capacity of energy storage and the superior power-law in the collective charging, provide an insight to exploit an efficient quantum battery based on the spin-spin-environment model.

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Section: Introductionmentioning

confidence: 99%

High-capacity and high-power collective charging with spin chargers

Huangfu,

Jing

2021

Preprint

Self Cite

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“…Extensive works have been put forward to protect entanglement or coherence in spin systems [16][17][18][19][20][21][22][23]. And it has been found that strong system-environment couplings [17], low temperatures [18] and initial system-environment correlations [20] play an important role in the dynamics of spin systems.…”

Section: Introductionmentioning

confidence: 99%

Entanglement Dynamics of Two Spins in Initially Correlated Wheel-Shaped Spin Baths

et al. 2015

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We study the effects of the initial correlations in environment on the entanglement dynamics of spin system. The correlated environment is novelly simulated by two correlated wheel-shaped spin baths, each consisting of an intermediate spin interacting with a spin-ring. The correlations in environment are achieved by the entanglement between two intermediate spins. The spin system includes two system-spins, and the interaction between the spin system and the environment is implemented by the coupling between the systemspin and the intermediate spin. Firstly, we analyze the influences of the initial entanglement between the two intermediate spins, the coupling parameters and the temperature of the baths on the entanglement dynamics of the two system-spins in equivalent subsystems. It is demonstrated that the initial entanglement between the baths can act as a resource for the generation and the revivals of the entanglement of the system-spins. Moreover, the amount of the generation and the revivals of the entanglement of the system-spins can be enhanced by regulating the coupling constants and the temperature of the baths. In addition, we also investigate the influences of different coupling ratios in non-equivalent subsystems, it is found that changing the coupling ratios of two subsystems has a significant effect on the generation and revivals of entanglement of system-spins.

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“…with the first term the Hamiltonian describing the subsystem S, the second term describes the Hamiltonian of the bath B, and the third term the Hamiltonian describing the coupling between the subsystem S and the bath B. Spin baths have been studied since at least the time of Fermi [4], and are also of recent interest [5,6,7]. In this paper we assume that the subsystem S consists of one spin-1/2 particle, also called the central spin, and that the bath B is composed of N spin-1/2 particles.…”

Section: Introductionmentioning

confidence: 99%

An Efficient Algorithm for Simulating the Real-Time Quantum Dynamics of a Single Spin-1/2 Coupled to Specific Spin-1/2 Baths

Novotny

Guerra

Raedt

et al. 2012

J. Phys.: Conf. Ser.

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An efficient algorithm for the computation of the real-time dependence of a single quantum spin-1/2 coupled to a specific set of quantum spin-1/2 baths is presented. The specific spin baths have couplings only with the spin operators S x between bath spins and the central spin. We calculate spin expectation values, the quantum purity, the von Neumann entropy, and the off-diagonal components of the reduced density matrix for the central spin once the bath spins have been traced out. The algorithm does not require the storage of any vector larger than of size 2, even though the size of the Hilbert space is 2 N+1 , where N is the number of bath spins. Results are presented for the central spin connected to different sizes and types of spin baths, and for different initial states for the central spin and for the bath spins. Results are also compared to those for more general baths.

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Entanglement dephasing dynamics driven by a bath of spins

Cited by 10 publications

References 43 publications

High-capacity and high-power collective charging with spin chargers

High-capacity and high-power collective charging with spin chargers

Entanglement Dynamics of Two Spins in Initially Correlated Wheel-Shaped Spin Baths

An Efficient Algorithm for Simulating the Real-Time Quantum Dynamics of a Single Spin-1/2 Coupled to Specific Spin-1/2 Baths

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