Mapping bifurcation structure and parameter dependence in quantum dot spin-VCSELs

Stability Analysis of Quantum-Dot Spin-VCSELs

Spin-polarized vertical-cavity surface-emitting lasers (spin-VCSELs) and vertical external-cavity surface-emitting lasers (spin-VECSELs) are of interest since their output polarization can be manipulated by spin-selective pumping, either optical or electrical. These devices, using quantum dot (QD) material for the active region, have shown instability (periodic oscillations) and polarization sw...

Magnetic field dependence of the spin- 2 and spin-1 Kondo effects in a quantum dot

C. H. L. Quay,1 John Cumings,1,* S. J. Gamble,2 R. de Picciotto,3 H. Kataura,4 and D. Goldhaber-Gordon1 1Physics Department, Stanford University, Stanford, California 94305-4060, USA 2Applied Physics Department, Stanford University, Stanford, California 94305-4090, USA 3Bell Laboratories, Alcatel Lucent, Murray Hill, New Jersey 07974, USA 4Nanotechnology Research Institute, National Institute o...

Spin-Based Quantum Dot Quantum Computing

Nonadiabatic two-parameter charge and spin pumping in a quantum dot.

We study dc charge and spin transport through a weakly coupled quantum dot, driven by a nonadiabatic periodic change of system parameters. We generalize the model of Tien and Gordon to simultaneously oscillating voltages and tunnel couplings. When applying our general result to the two-parameter charge pumping in quantum dots, we find interference effects between the oscillations of the voltage...

Quantum-Dot Spin Qubit and Hyperfine Interaction

We review our investigation of the spin dynamics for two electrons confined to a double quantum dot under the influence of the hyperfine interaction between the electron spins and the surrounding nuclei. Further we propose a scheme to narrow the distribution of difference in polarization between the two dots in order to suppress hyperfine induced decoherence.