Spin thermoelectrics in a disordered Fermi gas

Abstract

We study the connection between the spin-heat and spin-charge response in a disordered Fermi gas with spin-orbit coupling. It is shown that the ratio between the above responses can be expressed as the thermopower S = −(πk B ) 2 T σ /3eσ times a number R s which depends on the strength and type of the spin-orbit couplings considered. The general results are illustrated by examining different two-dimensional electron or hole systems with different and competing spin-orbit mechanisms, and we conclude that a metallic system could prove much more efficient as a heat-to-spin than as a heat-to-charge converter.

Berry Phase Effects in Dipole Density and the Mott Relation

“…We further divide it into two parts: ρ θ tot = ρ θ loc + δρ θ loc , where the former is the contribution from f and the latter from δf . In the following, we focus on ρ θ loc while the arXiv:1812.11721v3 [cond-mat.mes-hall] 16 Apr 2019 discussion of δρ θ loc will be postponed to the end of the paper. Hereafter the symmetrization between operators that do not commutate to each other is implied.…”

Thermal spin polarization in bidimensional systems

“…The spin Nernst effect was studied theoretically (Lie and Xie, 2010;Tauber et al, 2012;Rothe et al, 2012;Dyrdał and Barnaś, 2012;Lyapilin, 2013;Borge et al, 2013) mainly in the low-temperature regime. Its behavior depends on the nature of spin-orbit interaction taken into account and is correlated with the zero-temperature spin Hall effect.…”

Room-temperature spin thermoelectrics in metallic films

“…Assuming homogeneous conditions and taking as driving fields an electric field E x and a temperature gradient ∇ x T , we are interested in the generation of (i) a y-spin polarization s y (Edelstein [9,10] and thermal Edelstein [4,5] effects); (ii) a z-polarized spin current flowing along y, j z y (spin Hall [6] and spin Nernst [2,3] effects). In the presence of spin-orbit coupling, i.e., when spin is not conserved, the spin current has a diffusion term even under homogeneous conditions [42]:…”

“…When considering metallic systems, two interesting phenomena stand out in this field: the spin Nernst effect [2,3] and thermally induced spin polarizations [4,5]. They consist in the generation of, respectively, a spin current or a spin polarization transverse to an applied temperature gradient.…”