Stephanie Droste, Sabine Andergassen, Janine Splettstoesser
We study the Josephson current through a double quantum dot with Rashba spin-orbit interaction in presence of local Coulomb repulsion. A magnetic field is applied to the system, with arbitrary orientation with respect to the spin-orbit field. We study the Josephson current through the system in the limit of infinite superconducting gap, allowing to access the exact many-particle states of the effective double-dot setup. We concentrate on the effects of Rashba spin-orbit interaction on the magnetic-field induced singlet-triplet transition in the molecular regime, and account for the angular dependence of the spin-orbit field with respect to the magnetic field direction, for the coupling asymmetries, detuning, Coulomb interaction and finite temperatures. At zero temperature, we find that the orthogonal component of the spin-orbit field exhibits a similar effect as the Coulomb interaction inhibiting the occurrence of a {\pi}-phase (a sign-reversal in the Josephson current) at zero gate voltage. At finite temperature, the {\pi}-phase at zero gate voltage is stabilized providing a new route to the experimental observability of this sign reversal.
View original:
http://arxiv.org/abs/1205.1291
No comments:
Post a Comment