Spin-preserving ultrafast carrier capture and relaxation in InGaAs quantum dots

Spin relaxation in quantum dots

Results are given for spin relaxation in quantum dots due to acoustic phonon-assisted flips of single spins at low temperatures. The dominant spin relaxation processes for varying dot size, temperature, and magnetic field are identified. These processes are mediated by the spin-orbit interaction and are described within a generalized effective mass treatment. Particular attention is given to ph...

Ultrafast carrier dynamics in an InAs/InGaAs quantum dots-in-a-well heterostructure.

Ultrafast differential transmission spectroscopy is used to explore temperature-dependent carrier dynamics in an InAs/InGaAs quantum dots-in-a-well heterostructure. Electron-hole pairs are optically injected into the three dimensional GaAs barriers, after which we monitor carrier relaxation into the two dimensional InGaAs quantum wells and the zero dimensional InAs quantum dots by tuning the pr...

Capture and release of carriers in InGaAs/GaAs quantum dots

We observe the ultrafast capture and release of charge carriers in InGaAs/GaAs quantum dots (QDs) at room-temperature with time-resolved terahertz spectroscopy. For excitation into the barrier states, a decay of the photoinduced conductivity, due to capture of carriers into the nonconducting QD states is observed. The increase of the decay time constant with increasing pump fluence is attribute...

A carrier relaxation bottleneck probed in single InGaAs quantum dots using integrated superconducting single photon detectors

Carrier dynamics in p-type InGaAs/GaAs quantum dots

In this study we investigate the carrier relaxation dynamics in p-type doped InGaAs/GaAs quantum dots using time-integrated and time-resolved photoluminescence. The experiment shows that while a strong phonon bottleneck is observed in the undoped samples, with a 680 ps rise time of the photoluminescence intensity, the intra-dot relaxation time (31 ps) of the p-type doped samples is reduced sign...