Nonequilibrium Electrical, Thermal and Spin Transport in Open Quantum Systems of Topological Superconductors, Semiconductors and Metals

Filling an empty lattice by local injection of quantum particles

“…In this subsection, we discuss the quantum Langevin equation (QLE) approach [36][37][38][39][40][41][42][43][44]. Given the bilinear nature of the entire setup, we can compute exactly the steady state properties of the lattice chain following this approach.…”

Electrical, thermal and thermoelectric transport in open long-range Kitaev chain

“…Baths are kept at thermal equilibrium before they are connected with the LRK chain at time t 0 ; after that the whole device evolves with time (t > t 0 ) to reach non-equilibrium steady-state. In non-equilibrium steady-state, transport properties can be derived by first taking the limit t 0 → −∞, and then integrating out the bath operators using quantum LEGF method, which has been extensively discussed in many previous articles [7,14,15,35,39,40]. For the sake of completeness, we have added a brief discussion about LEGF method in appendix.…”

“…Among the proposed models of topological superconductors, the Kitaev chain has attracted much attention due to its unique ability to host topologically nontrivial zero energy Majorana bound states (MBSs), which are expected to be the critical ingredient to realize topological quantum computers [3,5,6]. Under appropriate conditions, a pair of MBSs is developed at the edges of a 1D Kitaev chain and these MBSs have significant ramifications on the nonequilibrium electrical [1,3,7], thermal, and thermoelectrical [8][9][10][11][12][13][14][15] transport through the Kitaev chain. It is to be noted that all the parameters, e.g.…”

“…It is known that the study of electrical and thermal currents in the SRK chain has been discussed in several literature, but such transport in the LRK chain has yet to be widely studied. To address this issue, we use the well-known quantum Langevin equations and Green's function (LEGF) method [7,14,15,35] to study electrical, thermal, and thermoelectric currents in the LRK chain. Baths are considered to be at thermal equilibrium described by Fermi distribution functions, which depend on the temperature and chemical potential of the corresponding baths.…”

Majorana differential shot noise and its universal thermoelectric crossover

“…Such experiments deal with nonequilibrium states which may be generated by bias voltages V or temperature differences ∆T , expressed equivalently through the corresponding thermal voltages V T , defined as eV T ≡ k B ∆T . Here Majorana features are predicted within the framework of mean currents I(V ) induced by mostly bias voltages or, to a lesser extent, mean currents I(V, V T ) induced by also temperature differences [37][38][39][40][41][42][43][44][45][46][47]. Experimental efforts on mean currents I(V ) induced by bias voltages [48][49][50] are aimed to measure the differential conductance ∂I(V )/∂V .…”