Kondo enhancement of current-induced spin accumulation in a quantum dot

Weak spin-orbit coupling produces very limited current-induced spin accumulation in nonmagnetic semiconductor nanostructures. We demonstrate a possibility to parametrically increase spin polarization using the Kondo effect. As a model object we consider a quantum dot side coupled to a quantum wire, taking into account spin-dependent electron tunneling from the wire to the dot. Using the nonequilibrium Green functions, we show that the many-body correlations between the quantum dot and the quantum wire can increase the current-induced spin accumulation at low temperatures by almost two orders of magnitude for moderate system parameters. The enhancement is related to the Kondo peak formation in the density of states and the spin instability due to the strong Coulomb interaction. This effect may be useful to electrically manipulate the localized electron spins in quantum dots for their quantum applications.