Spin-dependent Seebeck effect in Aharonov–Bohm rings with Rashba and Dresselhaus spin–orbit interactions

Abstract

ABSTRACT:We theoretically investigate the spin-dependent Seebeck effect in an Aharonov-Bohm mesoscopic ring in the presence of both Rashba and Dresselhaus spin-orbit interactions under magnetic flux perpendicular to the ring. We apply the Green's function method to calculate the spin Seebeck coefficient employing the tight-binding Hamiltonian. It is found that the spin Seebeck coefficient is proportional to the slope of the energy-dependent transmission coefficients. We study the strong dependence of spin Seebeck coefficient on the Fermi energy, magnetic flux, strength of spin-orbit coupling, and temperature. Maximum spin Seebeck coefficients can be obtained when the strengths of Rashba and Dresselhaus spin-orbit couplings are slightly different. The spin Seebeck coefficient can be reduced by increasing temperature and disorder.

Tuning the Aharonov-Bohm effect with dephasing in nonequilibrium transport

“…This genuine quantum effect with no classical counterpart has been verified in interference experiments [2][3][4][5][6][7]. Moreover, the relation of spin-orbit coupling and the AB effect has been investigated and discussed in relation to thermal properties [8][9][10]. Yet, the coherent dynamics of quantum particles is sensitive to dephasing processes, which appear due to couplings to the thermal environment.…”

“…In Fig. 8(b)-(d), we investigate the transition rate g µν determining the thermally induced transitions between eigenstates µ to ν in the Redfield equation (10). For the rate g 12 at φ = π we find a crossover from an increasing rates for small γ to a decreasing rate at large γ.…”

“…where ρ s denotes the steady states of the system with ρs = 0 for the dynamics in Eq. (10). The denominator ensures the normalization…”

Spin-Seebeck effect and spin polarization in a multiple quantum dot molecule

“…Pure spin Seebeck coefficients have been found for diverse setups, in where closed Aharonov-Bohm ring is one of the most studied, such as for Rashba QD molecules rings, 24,25 for a degenerated molecular QD in a ring, 26 and for a mesoscopic ring in the presence of both Rashba and Dresselhaus spin-orbit interactions. 27 Coulomb correlation in a single QD in the presence of metal and magnetic insulator leads, has also been proved to tune and enhance the SSE, leading to an efficient thermovoltaic transistor. 28 A T-shaped strongly coupled double QD system has been shown recently to exhibit SSE in the regime of the second stage of the Kondo effect.…”