Longitudinal and transverse exciton-spin relaxation in a single InAsP quantum dot embedded inside a standing InP nanowire using photoluminescence spectroscopy

Abstract

We have investigated the optical properties of a single InAsP quantum dot embedded in a standing InP nanowire. Elongation of the transverse exciton-spin relaxation time of the exciton state with decreasing excitation power was observed by first-order photon correlation measurements. This behavior is well explained by the motional narrowing mechanism induced by Gaussian fluctuations of environmental charges in the nanowire. The longitudinal exciton-spin relaxation time is evaluated by the degree of the random polarization of emission originating from exciton states confined in a single-nanowire quantum dot by using Mueller calculus based on Stokes parameters representation. The reduction in the random polarization component with decreasing excitation power is caused by suppression of the exchange interaction of electron and hole due to an optically induced internal electric field by the dipoles at the wurtzite and zinc-blende heterointerfaces in the InP nanowire.

Size control of InP nanowires by in situ annealing and its application to the formation of InAsP quantum dots

“…The results indicated that the integrated intensity of peaks X and XX were proportional to linear and quadratic dependence on I, respectively, when I was sufficiently low. These were very similar to our previous results reported in [49][50][51]. The peak at 0.802 eV observed above I = 17.7 W cm −2 was not identified but presumably originated from a charged exciton.…”

Multiqubit spectroscopy of Gaussian quantum noise

“…In our simulations, we used parameters relevant to exciton quantum dots interacting with phonons in one-dimensional (1D) geometries, such as nano-wires or carbon nanotubes [50,57,58]. As is characteristic of 1D geometries, the spectral density of the bath was Ohmic,…”

Single-photon emission from InAsP quantum dots embedded in density-controlled InP nanowires

“…The formation of NW-QDs by InP-based materials by a catalyst-assisted vapor-liquid-solid (VLS) mechanism 22,23) or selective-area metalorganic vapor phase epitaxy (SA-MOVPE) 5,24) has been studied towards achieving a single-photon emitter in the optical communication band. Detailed studies have been carried out on their optical properties 25) and single-photon emission 23,24) and entangled photon emission 26) has been demonstrated in these studies. Some of the remaining issues of NW-QD-based single-photon emitters are the control of emission wavelength and electrically driven operation.…”