ﻻ يوجد ملخص باللغة العربية
We propose an efficient mechanism for the operation of writing spin in a quantum dot, which is an ideal candidate for qubit. The idea is based on the Andreev reflection induced spin polarization (ARISP) in a ferromagnetic / quantum-dot / superconductor system. We find that on the resonance of Andreev reflection, the spin polarization of quantum dot strongly denpends on the magnetization of ferromagnetic electrode, and the sign of the spin polarization is controllable by bias voltage. In the presence of intradot Coulomb interaction, we show that ARISP effect can still survive as long as the charging energy is comparable to the superconducting gap. Detailed conditions and properties of ARISP are also discussed.
Using a laterally-fabricated quantum-dot (QD) spin-valve device, we experimentally study the Kondo effect in the electron transport through a semiconductor QD with an odd number of electrons (N). In a parallel magnetic configuration of the ferromagne
We theoretically study the spin-polarized transport through a single-molecule magnet, which is weakly coupled to ferromagnetic leads, by means of the rate-equation approach. We consider both the ferromagnetic and antiferromagnetic exchange-couplings
We have fabricated a lateral double barrier magnetic tunnel junction (MTJ) which consists of a single self-assembled InAs quantum dot (QD) with ferromagnetic Co leads. The MTJ shows clear hysteretic tunnel magnetoresistance (TMR) effect, which is evi
We study spin-resolved noise in Coulomb blockaded double quantum dots coupled to ferromagnetic electrodes. The modulation of the interdot coupling and spin polarization in the electrodes gives rise to an intriguing dynamical spin $uparrow$-$uparrow$
A correct general formula for the spin current through an interacting quantum dot coupled to ferromagnetic leads with magnetization at an arbitrary angle $theta$ is derived within the framework of the Keldysh formalism. Under asymmetric conditions, t