Strongly temperature-dependent recombination kinetics of a negatively charged exciton in asymmetric quantum dots at 1.55 μm
arXiv:1807.02836 · doi:10.1063/1.5030895
Abstract
We report on strongly temperature-dependent kinetics of negatively charged carrier complexes in asymmetric InAs/AlGaInAs/InP quantum dots (dashes) emitting at telecom wavelengths. The structures are highly elongated and of large volume, which results in atypical carrier confinement characteristics with - shell energy splittings far below the optical phonon energy, which strongly affects the phonon-assisted relaxation. Probing the emission kinetics with time-resolved microphotoluminescence from a single dot, we observe a strongly non-monotonic temperature dependence of the charged exciton lifetime. Using a kinetic rate-equation model, we find that a relaxation side-path through the excited charged exciton triplet states may lead to such behavior. This, however, involves efficient singlet-triplet relaxation via the electron spin-flip. Thus, we interpret the results as an indirect observation of strongly enhanced electron spin relaxation without magnetic field, possibly resulting from atypical confinement characteristics.
arXiv comment5 pages, 5 figures
References in corpus (12)
- Spin relaxation in semiconductor quantum dots
- Spin-flip transitions between Zeeman sublevels in semiconductor quantum dots
- Generation of heralded entanglement between distant hole spins
- Phase-tuned entangled state generation between distant spin qubits
- Realization of a cascaded quantum system: heralded absorption of a single photon qubit by a single-electron charged quantum dot
- Exciton lifetime and emission polarization dispersion in strongly in-plane asymmetric nanostructures
- Picosecond charge variation of quantum dots under pulsed excitation
- Radiative cascades in charged quantum dots
- Decoherence-assisted initialization of a resident hole spin polarization in a two-dimensional hole gas
- Dominant role of the shear strain induced admixture in spin-flip processes in self-assembled quantum dots
- Optical initialization of hole spins in p-doped quantum dots: orientation efficiency and loss of coherence
- Spin dynamics and magneto-optical response in charge-neutral tunnel-coupled quantum dots