Exact dynamics of interacting qubits in a thermal environment: results beyond the weak coupling limit

Wu, Lian-Ao; Yu, Claire X.; Segal, Dvira

doi:10.1088/1367-2630/15/2/023044

Cited by 11 publications

(9 citation statements)

References 65 publications

(133 reference statements)

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“…Consider a system consisting of a pair of interacting qubits, with one or both qubits coupled to a thermal reservoir, as treated in, for instance [17,[35][36][37], with the coupling between the qubits being allowed to vary from some initially strong value, to zero. The model could be used, for instance, to study the work done by allowing the coupling between the qubits to decrease to zero (which would be equivalent, e.g., to 'separating the qubits' if the coupling is modelled as dipole interaction).…”

Section: A Damped Coupled Qubitsmentioning

confidence: 99%

Coarse-graining in the derivation of Markovian master equations and its significance in quantum thermodynamics

Cresser,

Facer

2017

Preprint

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The coarse-graining approach to deriving the quantum Markovian master equation is revisited, with close attention given to the underlying approximations. It is further argued that the time interval over which the coarse-graining is performed is a free parameter that can be given a physical measurement-based interpretation. In the case of the damping of composite systems to reservoirs of different temperatures, currently of much interest in the study of quantum thermal machines with regard to the validity of 'local' and 'global' forms of these equations, the coupling of the subsystems leads to a further timescale with respect to which the coarse-graining time interval can be chosen. Different choices lead to different master equations that correspond to the local and global forms. These can be then understood as having different physical interpretations based on the role of the coarse-graining, as well as different limitations in application.

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Section: A Damped Coupled Qubitsmentioning

confidence: 99%

Coarse-graining in the derivation of Markovian master equations and its significance in quantum thermodynamics

Cresser,

Facer

2017

Preprint

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“…In this consideration, the decohorence factors yield ( ) The absolute value of the decoherence factor 14 F is evaluated in the thermodynamics limit as in Ref. [21] ( ) …”

Section: Modelmentioning

confidence: 99%

“…The concept of thermal entanglement is one of the important concepts in quantum correlation because it shows the effect of thermal fluctuations on entanglement [14]. The maximization scheme for thermal entanglement for two interacting qubits has been proposed in Ref.…”

Section: Introductionmentioning

confidence: 99%

Tailoring Quantum Correlations of a Coupled Central Two Qubits Soaked in a Finite Temperature Antiferromagnetic Environment with Frequency Gap

Fai¹,

Afuoti²,

Fouokeng³

et al. 2014

JQIS

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We revisit the quantum features of an anti-ferromagnetic (AF) spin environment at finite temperature with gap in its frequency spectrum, on the dynamics quantum correlations of a coupled central two qubits system with Dzyaloshinskii-Moriya (DM) interaction, prepared in two entangled Bell states. Using entanglement and quantum discord as quantum meters of decoherence, the prepared entangled states are classified as robust or fragile relative to the degree of information leakage to the AF environment. By tailoring the size of the frequency gap, anisotropy field strength and induced field, due to system AF spin environment coupling, size of the AF environment and DM interaction parameter, a decoherence-free sub-space can be accessed for efficient execution of quantum protocols encoded in the entangled states.

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“…For a subsystem which constitutes of two interacting spins, this situation effectively corresponds to a subsystem unharmonically coupled to a bosonic bath, allowing to introduce nonlinear effects [10]. Exact dynamics of interacting TLS immersed in separate thermal reservoirs or within a common bath has also been studied [11]. For the device design, such as in molecular devices, people often need to consider the scaling of heat current with system size and time in order to prevent the devices from disintegrating [12,13], because excess heat build-up during operation may cause device disintegrating.…”

Section: Introductionmentioning

confidence: 99%

Quantum energy transfer between nonlinearly-coupled bosonic bath and a fermionic chain: an exactly solvable model

Wang,

Luo,

et al. 2019

Preprint

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The evolution of a quantum system towards thermal equilibrium is usually studied by approximate methods, which have their limits of validity and should be checked against analytically solvable models. In this paper, we propose an analytically solvable model to investigate the heat transfer between a bosonic bath and a fermionic bath which are nonlinearly-coupled to each other. The bosonic bath consists of an infinite collection of non-interacting bosonic modes, while the fermionic bath is represented by a chain of interacting fermions with nearest-neighbor interactions. We compare behaviors of the temperature-dependent heat current JT and temperature-independent heat current JT I for different bath configurations. With respect to the bath spectrum, JT decays exponentially for Lorentz-Drude type bath, which is the same as the conventional approximations. On the other hand, the decay rate is 1/t 3 for Ohmic type and 1/t for white noise, which doesn't have conventional counterparts. For the temperature-independent current JT I , the decay rate is divergent for the Lorentz-Drude type bath, 1/t 4 for the Ohmic bath, and 1/t for the white noise. When further considering the dynamics of the fermionic chain, the current will be modulated based on the envelope from the bath. As an example, for a bosonic bath with Ohmic spectrum, when the fermionic chain is uniformly-coupled, we have JT ∝ 1/t 6 and JT I ∝ 1/t 3 . Remarkably, for perfect state transfer (PST) couplings, there always exists an oscillating quantum heat current JT I . Moreover, it is interesting that JT is proportional to (N − 1) 1/2 at certain times for PST couplings under Lorentz-Drude or Ohmic bath.

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Exact dynamics of interacting qubits in a thermal environment: results beyond the weak coupling limit

Cited by 11 publications

References 65 publications

Coarse-graining in the derivation of Markovian master equations and its significance in quantum thermodynamics

Coarse-graining in the derivation of Markovian master equations and its significance in quantum thermodynamics

Tailoring Quantum Correlations of a Coupled Central Two Qubits Soaked in a Finite Temperature Antiferromagnetic Environment with Frequency Gap

Quantum energy transfer between nonlinearly-coupled bosonic bath and a fermionic chain: an exactly solvable model

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