arXiv subjects

Ol'ga V. Dimitrova

Publications and source records attributed to Ol'ga V. Dimitrova.

4 recordsLinked to original sources

arXiv2005

2D SNS junction with Rashba spin-orbit interaction

The effect of Rashba spin-orbital interaction upon supercurrent in S-2DEG-S proximity junctions is investigated in the clean limit. Generalization of Beenakker's formula for Andreev levels to the case of spin-orbital scattering is presented. Spin-orbit - induced splitting of Andreev bound-states is predicted for a junction of infinite width, and with non-vanishing normal backscattering at S/N interfaces. Semiclassical average of the Josephson current is however insensitive to the Rashba coupling as long as electron-electron interaction in 2DEG is neglected.

cond-mat.mes-hall↗

arXiv2004

Vanishing Spin-Hall Conductivity in 2D disordered Rashba electron gas

For the two-dimensional ideal electron gas with the Rashba spin-orbit interaction and in the presence of non-magnetic short-ranged potential impurities the spin-Hall conductivity $σ_{sH}$ is found by direct microscopic calculation. Within the semiclassical approximation $\hbar/τ\ll ε_F$ and $Δ\ll ε_F$ the value of $σ_{sH}$ is zero for arbitrary ratio of the spin-orbit splitting $Δ$ and the inverse elastic scattering time $1/τ$.

cond-mat.mes-hall↗

arXiv2004

Spin-Hall Conductivity and Pauli Susceptibility in the Presence of Electron-Electron Interactions

We found the universal relationship between frequency-dependent spin-Hall conductivity and magnetic susceptibility in clean 2D electron systems with Rashba coupling: $σ_{sH}(Ω)= \frac{e}{(gμ_B)^2m_b}χ_\parallel(Ω)$ in the presence of an arbitrary two-particle spin-conserving interaction. We show that the Coulomb interaction renormalizes the spin-Hall constant. The magnitude of the relative correction to $σ_{sH}$ is proportional to the Coulomb interaction parameter $e^2/εv_F\hbar$ and does not depend on the strength of the Rashba coupling $α$.

cond-mat.mes-hall↗

arXiv2004

Phase diagram of a surface superconductor in parallel magnetic field

Detailed theory of phase diagram of clean 2D surface superconductor in a parallel magnetic field is presented. Regular spin-orbital interaction of the Rashba type is known to produce inhomogeneous superconductive state similar to the Larkin-Ovchinnikov-Fulde-Ferrel (LOFF) state with $Δ({\bf r})\propto \cos({\bf Qr})$ at high magnetic fields, with $Q \sim gμ_B h/v_F$. We consider the case of relatively strong Rashba interaction and show that at low temperatures $T\leq 0.4 T_{c0}$ the LOFF-type state is separated from the usual homogeneous state by the first-order phase transition line. At higher temperatures new "helical" state with $Δ({\bf r}) \propto \exp(i{\bf Qr})$ intervene between uniform BCS state and LOFF-like state. One component of superfluid density tensor $n_s$ vanishes on the second-order transition line between BCS state and helical state. Nonmagnetic impurities suppresses both inhomogeneous states, and eliminate them completely at $T_{c0}τ\leq 0.11$.

cond-mat.supr-con↗