Memory Effect in Upper Bound of Heat Flux Induced by Quantum Fluctuations

Quantum-like behavior of 1D nonequilibrium system in the maximum heat flux limit

Using information entropy formalism, we consider a one-dimensional system with heat flux and extend the meaning of equilibrium variables to non equilibrium scenarios when classical local equilibrium approach is not applicable; this is particularly important for the performance evaluation of modern thermal systems and microdevices, which usually operate in extreme situations. The extended non equilibrium entropy, temperature, thermal conductivity and heat capacity have been analyzed as functions of the local energy density (kinetic temperature) and heat flux.

Dynamic control of quantum geometric heat flux in a nonequilibrium spin-boson model

We study the quantum geometric heat flux in the nonequilibrium spin-boson model. By adopting the noninteracting-blip approximation that is able to accommodate the strong system-bath coupling, we show that there exists a nonzero geometric heat flux only when the two-level system is nondegenerate. Moreover, the pumping, no pumping, and dynamic control of geometric heat flux are discussed in detail, compared to the results with Redfield weak-coupling approximation. In particular, the geometric energy transfer induced by modulation of two system-bath couplings is identified, which is exclusive to …

线性量子系统中通过合成场的非互易热通量

Nonreciprocal heat flux via synthetic fields in linear quantum systems

本文研究线性量子系统中合成场诱导的非互易热传递，提出基于主方程和朗之万方程的两种方法，在四谐振子链中实现总热通量整流。

Nanoscale heat flux between anisotropic uniaxial media

We present a theoretical study of near-field heat transfer between two anisotropic materials separated by a small vacuum gap and maintained in a stationary non-equilibrium thermal situation. By combining standard stochastic electrodynamics and the Maxwell-Garnett description for effective media, we show that heat flux can be significantly enhanced by air inclusions. This result is explained by : (a) the presence of extraordinary surface waves that give rise to supplementary channels for heat transfer throughout the gap, (b) an increase in the contribution given by the ordinary surface waves at…

Measurement and dephasing of a flux qubit due to heat currents

We study a flux qubit, made of a superconducting loop interrupted by three Josephson junctions, which is subject to a temperature gradient. We show that the heat current induced by the temperature gradient, being sensitive to the superconducting phase differences at the junctions, depends significantly on the state of the qubit. We furthermore investigate the impact of the heat current on the coherence properties of the qubit state. We have found that even small temperature gradients can lead to dephasing times of the order of microseconds for the Delft-qubit design.

Quantum memory using a hybrid circuit with flux qubits and NV centers

We propose how to realize high-fidelity quantum storage using a hybrid quantum architecture including two coupled flux qubits and a nitrogen-vacancy center ensemble (NVE). One of the flux qubits is considered as the quantum computing processor and the NVE serves as the quantum memory. By separating the computing and memory units, the influence of the quantum computing process on the quantum memory can be effectively eliminated, and hence the quantum storage of an arbitrary quantum state of the computing qubit could be achieved with high fidelity. Furthermore the present proposal is robust with…