Intraband relaxation process in PbSe quantum dot studied by lattice relaxation method

Excited-state relaxation in PbSe quantum dots.

In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings ("phonon-bottleneck"). However, excited-state relaxation was observed to...

Spin-Lattice Relaxation in Si Quantum Dots

We consider spin-lattice relaxation processes for electrons trapped in lateral Si quantum dots in a [001] inversion layer. Such dots are characterized by strong confinement in the direction perpendicular to the surface and much weaker confinement in the lateral direction. The spin relaxation is assumed to be due to the modulation of electron g-factor by the phonon-induced strain, as was shown p...

Intraband carrier photoexcitation in quantum dot lasers.

We unveil the role of bound-to-continuum photoexcitation of carriers as a relevant process that affects the performance of quantum dot (QD) lasers. We present the response of an InAs/InGaAs QD laser to a sub-band gap pump, showing an unexpected depletion of the emitted photons. We relate this observation with carrier photoexcitation through additional transmission and photocurrent measurements....

Intraband transitions in quantum dot-superlattice heterostructures

Electrical control of spin relaxation in a quantum dot.

We demonstrate electrical control of the spin relaxation time T1 between Zeeman-split spin states of a single electron in a lateral quantum dot. We find that relaxation is mediated by the spin-orbit interaction, and by manipulating the orbital states of the dot using gate voltages we vary the relaxation rate W identical withT1(-1) by over an order of magnitude. The dependence of W on orbital co...