[Show abstract][Hide abstract] ABSTRACT: We demonstrate the real-time detection of single photogenerated electrons in
two different lateral double quantum dots made in AlGaAs/GaAs/AlGaAs quantum
wells having a thin or a thick AlGaAs barrier layer. The observed incident
laser power and photon energy dependences of the photoelectron detection
efficiency both indicate that the trapped photoelectrons are, for the thin
barrier sample, predominantly photogenerated in the buffer layer followed by
tunneling into one of the two dots, whereas for the thick barrier sample they
are directly photogenerated in the well. For the latter, single photoelectron
detection after selective excitation of the heavy and light hole state in the
dot is well resolved. This ensures the applicability of our quantum well-based
quantum dot systems for the coherent transfer from single photon polarization
to single electron spin states.
[Show abstract][Hide abstract] ABSTRACT: We demonstrate one and two photoelectron trapping and the subsequent dynamics associated with interdot transfer in double quantum dots over a time scale much shorter than the typical spin lifetime. Identification of photoelectron trapping is achieved via resonant interdot tunneling of the photoelectrons in the excited states. The interdot transfer enables detection of single photoelectrons in a nondestructive manner. When two photoelectrons are trapped at almost the same time we observed that the interdot resonant tunneling is strongly affected by the Coulomb interaction between the electrons. Finally the influence of the two-electron singlet-triplet state hybridization has been detected using the interdot tunneling of a photoelectron.
[Show abstract][Hide abstract] ABSTRACT: We demonstrate single-shot detection of single electrons generated by single photons using an electrically tunable quantum dot and a quantum point contact charge detector. By tuning the quantum dot in a Coulomb blockade before the photoexcitation, we observe the trapping and subsequent resetting of single photogenerated electrons. The photogenerated electrons can be stored in the dot for a tunable time range from shorter to longer than the spin-flip time T1. We combine this trap-reset technique with spin-dependent tunneling under magnetic fields to observe the spin-dependent photon detection within the T1.
[Show abstract][Hide abstract] ABSTRACT: We present the implementation of a system for the quantum state transfer between electron spin and photons exploiting the coupling of an InAs self-assembled quantum dot to a superconducting resonator cavity.
Journal of Physics Conference Series 09/2010; 245(1):012024.