Spin-polarized tunneling through a diluted magnetic semiconductor quantum dot

Spin-polarized electron tunneling across magnetic dielectric

This letter deals with a magnetic tunnel junction having spin filtering by a magnetic barrier. We performed experiments in which a relatively strong external field rotates magnetizations of both ferromagnetic electrodes in the tunnel junction with the magnetic barrier simultaneously so that the two are always parallel to each other. The tunnel magnetoresistance induced in this way was over 16% ...

Quantum interference effect in electron tunneling through a quantum-dot-ring spin valve

Spin-dependent transport through a quantum-dot (QD) ring coupled to ferromagnetic leads with noncollinear magnetizations is studied theoretically. Tunneling current, current spin polarization and tunnel magnetoresistance (TMR) as functions of the bias voltage and the direct coupling strength between the two leads are analyzed by the nonequilibrium Green's function technique. It is shown that th...

Resonant tunneling through quantum-dot arrays.

Spin Selection Through a Quantum Dot

621 Staying in Sync In parallel processing, computational tasks are assigned to many computers at once. However, a difficulty is that when several computers are working independently, one processor can get well ahead of the others on its part of the problem. As a result, progress tends to diverge or spread greatly as the number of processors used increases. Korniss et al. (p. 677; see the Persp...

Optical properties of a semiconductor quantum dot with a single magnetic impurity: photoinduced spin orientation

We describe the optical resonant manipulation of a single magnetic impurity in a self-assembled quantum dot. We show that using the resonant pumping one can address and manipulate selectively individual spin states of a magnetic impurity. The mechanisms of resonant optical polarization of a single impurity in a quantum dot involve anisotropic exchange interactions and are different than those i...