Thermoelectric effects in graphene with local spin-orbit interaction

Abstract

We investigate the transport properties of a graphene layer in the presence of Rashba spin-orbit interaction. Quite generally, spin-orbit interactions induce spin splittings and modifications of the graphene band structure. We calculate within the scattering approach the linear electric and thermoelectric responses of a clean sample when the Rashba coupling is localized around a finite region. We find that the thermoelectric conductance, unlike its electric counterpart, is quite sensitive to external modulations of the Fermi energy. Therefore, our results suggest that thermocurrent measurements may serve as a useful tool to detect nonhomogeneous spin-orbit interactions present in a graphene-based device. Furthermore, we find that the junction thermopower is largely dominated by an intrinsic term independently of the spin-orbit potential scattering. We discuss the possibility of canceling the intrinsic thermopower by resolving the Seebeck coefficient in the subband space. This causes unbalanced populations of electronic modes which can be tuned with external gate voltages or applied temperature biases.

Enhanced valley-resolved thermoelectric transport in a magnetic silicene superlattice

“…This means that like the spin-dependent Seebeck effect, we can use this valley-dependent Seebeck effect to generate a valley voltage bias [27,30]. ) the transmission magnitudes never decay with increasing V. These results are similar to those observed for topological insulator ultrathin films [31] but quite different from those for conventional 2D electron gas.…”

“…In the linear response regime, i.e., T T T L R ≈ = , we calculate the valley-and spin-resolved thermopower S , η σ [27,30]: In analogy with S s , we also define the valley-dependent thermopower S v :…”

Effect of impurity resonant states on optical and thermoelectric properties on the surface of a topological insulator

“…From the behavior of the transverse Peltier (or Nernst) conductivity at low temperatures, one can estimate the magnitude of the gap induced by time-reversal symmetry breaking and so be used to map the Berry phase structure 34 . Thermoelectric effects is also applied to detect the local spin-orbit interaction in graphene 35 . Employing the thermoelectric properties 36 , clear signatures of the topological surface states are extracted from the bulk states.…”

Exact results relating spin–orbit interactions in two-dimensional strongly correlated systems

“…Using now the total z-spin component operator from (10), and applying the relations Ψ g |n d k,↑ |Ψ g = |γ 1,k | 2 + |γ 2,k | 2 + |γ 3,k | 2 , Ψ g |n d k,↓ |Ψ g = |γ 1,k | 2 + |γ 2,k | 2 + |γ 4,k | 2 , Ψ g |n f k,↑ |Ψ g = |γ 1,k | 2 + |γ 3,k | 2 + |γ 4,k | 2 , Ψ g |n f k,↓ |Ψ g = |γ 2,k | 2 + |γ 3,k | 2 + |γ 4,k | 2 ,(C5) one finds for the ground state expectation value ofŜ z per site the expression Ŝ z N sit = 1 2N sit k |γ 3,k | 2 − |γ 4,k | 2 + |γ 1,k | 2 − |γ 2,k | 2 |γ 1,k | 2 + |γ 2,k | 2 + |γ 3,k | 2 + |γ 4,k | 2 .…”