P. Schwab

Spin-Hall effect in a disordered two-dimensional electron system

We calculate the spin-Hall conductivity for a two-dimensional electron gas within the self-consistent Born approximation, varying the strength and type of disorder. In the weak disorder limit we find both analytically and numerically a vanishing spin-Hall conductivity even when we allow a momentum dependent scattering. Separating the reactive from the dissipative current response, we find the universal value

Quasiclassical approach to the spin-Hall effect in the two-dimensional electron gas

{\ensuremath{\sigma}}_{sH}^{R}=e∕8\ensuremath{\pi}

Anderson Localization versus Delocalization of Interacting Fermions in One Dimension

for the reactive response, which cancels however with the dissipative part

Spin-orbit interaction in a two-dimensional electron gas: A SU(2) formulation†

{\ensuremath{\sigma}}_{sH}^{D}=\ensuremath{-}e∕8\ensuremath{\pi}

Persistent Currents Versus Phase Breaking in Mesoscopic Metallic Samples

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Spin-charge locking and tunneling into a helical metal

We study the spin-charge coupled transport in a two-dimensional electron system using the method of quasiclassical (

Normal persistent currents

\ensuremath{\xi}

Non-Abelian gauge fields in the gradient expansion: Generalized Boltzmann and Eilenberger equations

-integrated) Greens functions. In particular we derive the Eilenberger equation in the presence of a generic spin-orbit field. The method allows us to study spin and charge transport from ballistic to diffusive regimes and continuity equations for spin and charge are automatically incorporated. In the clean limit we establish the connection between the spin Hall conductivity and the Berry phase in momentum space. For finite systems we solve the Eilenberger equation numerically for the special case of the Rashba spin-orbit coupling and a two-terminal geometry. In particular, we calculate explicitly the spin Hall induced spin polarization in the corners, predicted by Mishchenko et al. [Phys. Rev. Lett. 93, 226602 (2004)]. Furthermore we find universal spin currents in the short-time dynamics after switching on the voltage across the sample, and calculate the corresponding spin Hall polarization at the edges. Where available, we find perfect agreement with analytical results.

Tuning the Spin Hall Effect in a Two-Dimensional Electron Gas

Using the density matrix renormalization group algorithm, we investigate the lattice model for spinless fermions in one dimension in the presence of a strong interaction and disorder. The phase sensitivity of the ground state energy is determined with high accuracy for systems up to a size of 60 lattice constants. This quantity is found to be log-normally distributed. The fluctuations grow algebraically with system size with a universal exponent of ~2/3 in the localized region of the phase diagram. Surprizingly, we find, for an attractive interaction, a delocalized phase of finite extension. The boundary of this delocalized phase is determined.

Magnetoconductance of a two-dimensional metal in the presence of spin-orbit coupling

Spin-orbit interaction is usefully classified as extrinsic or intrinsic, depending on its origin: the potential due to random impurities (extrinsic), or the crystalline potential associated with the band or device structure (intrinsic). In this paper we will show how, by using a SU(2) formulation, the two sources may be described in an elegant and unified way. As a result we obtain a simple description of the interplay of the two types of spin-orbit interaction, and a physically transparent explanation of the vanishing of the d.c. spin Hall conductivity in a Rashba two-dimensional electron gas when spin relaxation is neglected, as well as its reinstatement when spin relaxation is allowed. Furthermore, we obtain an explicit formula for the transverse spin polarization created by an electric current, which generalizes the standard formula obtained by Edelstein, and Aronov and Lyanda-Geller by including extrinsic spin-orbit interaction and spin relaxation.