Spin-flip transitions between Zeeman sublevels in semiconductor quantum dots

We have studied spin-flip transitions between Zeeman sublevels in GaAs electron quantum dots. Several different mechanisms which originate from spin-orbit coupling are shown to be responsible for such processes. It is shown that spin-lattice relaxation for the electron localized in a quantum dot is much less effective than for the free electron. The spin-flip rates due to several other mechanisms not related to the spin-orbit interaction are also estimated.Comment: RevTex, 7 pages (extended journal version, PRB, in press

Magnetic anisotropy of critical current in nanowire Josephson junction with spin-orbit interaction

We develop and study theoretically a minimal model of semiconductor nanowire Josephson junction that incorporates Zeeman and spin-orbit effects. The DC Josephson current is evaluated from the phase-dependent energies of Andreev levels. Upon changing the magnetic field applied, the critical current oscillates manifesting cusps that signal the $0$-$\pi$ transition. Without spin-orbit interaction, the oscillations and positions of cusps are regular and do not depend on the direction of magnetic field. In the presence of spin-orbit interaction, the magnetic field dependence of the current becomes anisotropic and irregular. We investigate this dependence in detail and show that it may be used to characterize the strength and direction of spin-orbit interaction in experiments with nanowires.Comment: submitted to EPL. The manuscript has a supplementary note. 5 page with 4 figures + 2 pages with 2 figure

Electron Transport in Double Quantum Dot governed by Nuclear Magnetic Field

We investigate theoretically electron transfer in a doble dot in a situation where it is governed by nuclear magnetic field: This has been recently achieved in experiment. We show how to partially compensate the nuclear magnetic field to restore Spin Blockade