Wang Shikuan

Hangzhou Dianzi University · Department of Physics

Motivated by the development of bio-thermoelectricity and spin caloritronics, we studied the nonlinear spin-selective transport along a vibrating α-helical protein molecule in the presence of thermal bias by using the standard nonequilibrium Green’s function (NEGF) formalism. Our results demonstrate that the thermal bias induces the oscillation of...

Within the second-order non-Markovian master equation description, we develop an efficient method for calculating the noise spectrum of transport current through interacting mesoscopic systems. By introducing proper current-related density operators, we propose a practical and very efficient time-local approach to compute the noise spectrum, includ...

We investigate the nonequilibrium current noise spectrum of single impurity Anderson model quantum dot systems on the basis of the accurate dissipation equation of motion evaluations. By comparing between the equilibrium and nonequilibrium cases and between the non-Kondo and Kondo regimes, we identify the current noise spectrum of the nonequilibriu...

Motivated by the increasing demand for designing spin-polarized quantum devices via electric manipulation, we theoretically studied the spin polarization induced by Rashba spin-orbit interaction (RSOI) and the heat generated by thermal bias in the normal metal(N)-(insulator(I), Quantum Dot(QD))-Superconductor(S) ring threaded by a magnetic flux. We...

We systematically study the nonequilibirum Kondo mechanisms of quantum noise spectrum based on the accurate dissipaton--equation--of--motion evaluations. By comparing the noise spectra between the equilibrium and nonequilibrium cases and between the non-Kondo and Kondo regimes, we identify the nonequilibrium Kondo features in the current noise spec...

Triggered by the motivation of conquering the heat bottleneck facing nanoelectronics, we studied the current-induced heat generation in a quantum dot (QD) with the Andreev-Fano (AF) resonance. In the strong electron-phonon interaction regime, the formula of steady heat generation is extended by Nambu representation of nonequilibrium Green’s functio...

We investigate the dynamics of charge--states coherence in a degenerate double--dot Aharonov--Bohm interferometer with finite interdot Coulomb interactions. The quantum coherence of the charge states is found to be sensitive to the transport setup configurations, involving both the single--electron impurity channels and the Coulomb--assisted ones....

Based on the Yan's dissipaton equation of motion (DEOM) theory [J. Chem. Phys. 140, 054105 (2014)], we investigate the characteristic features of current noise spectrum in several typical transport regimes of a single-impurity Anderson model. Many well-known features such as Kondo features are correctly recovered by our DEOM calculations. More impo...

Several recent advancements for the hierarchical equations of motion (HEOM) approach are reported. First, we propose an a priori estimate for the optimal number of basis functions for the reservoir memory decomposition. Second, we make use of the sparsity of auxiliary density operators (ADOs) and propose two ansatzs to screen out all the intrinsic...

Within the frame of quantum dissipation theory, we develop a new hierarchical equations of motion theory, combined with the small polaron transformation. We fully investigate the electron transport of a single attractive impurity system with the strong electron-phonon coupling in charge- Kondo regime. Numerical results demonstrate the following fac...

We propose a hierarchical dynamics approach for evaluation of nonequilibrium dynamic response properties of quantum impurity systems. It is based on a hierarchical equations of motion formalism, in conjunction with a linear response theory established in the hierarchical Liouville space. This provides an accurate and universal tool for characteriza...

Inelastic electron transport in quantum dot systems is studied via the hierarchical equations of motion combining a small polaron transformation approach, with differential conductance dI/dV∼V characteristics being evaluated accurately at the cotunneling level. We observe (i) the peak feature of phonon emission Franck-Condon sidebands to the zero-p...

A systematic procedure for deriving the master equation of a dissipative system is reported in the framework of stochastic description. For the Caldeira-Leggett model of the harmonic-oscillator bath, a detailed and elementary derivation of the bath-induced stochastic field is presented. The dynamics of the system is thereby fully described by a sto...