Thermal stability of emission from single InGaAs/GaAs quantum dots at the telecom O-band

Abstract

Single-photon sources are key building blocks in most of the emerging secure telecommunication and quantum information processing schemes. Semiconductor quantum dots (QD) have been proven to be the most prospective candidates. However, their practical use in fiber-based quantum communication depends heavily on the possibility of operation in the telecom bands and at temperatures not requiring extensive cryogenic systems. In this paper we present a temperature-dependent study on single QD emission and single-photon emission from metalorganic vapour-phase epitaxy-grown InGaAs/GaAs QDs emitting in the telecom O-band at 1.3 μm. Micro-photoluminescence studies reveal that trapped holes in the vicinity of a QD act as reservoir of carriers that can be exploited to enhance photoluminescence from trion states observed at elevated temperatures up to at least 80 K. The luminescence quenching is mainly related to the promotion of holes to higher states in the valence band and this aspect must be primarily addressed in order to further increase the thermal stability of emission. Photon autocorrelation measurements yield single-photon emission with a purity of $${g}_{50K}^{(2)}\left(0\right)=0.13$$ g 50 K ( 2 ) 0 = 0.13 up to 50 K. Our results imply that these nanostructures are very promising candidates for single-photon sources at elevated (e.g., Stirling cryocooler compatible) temperatures in the telecom O-band and highlight means for improvements in their performance.

Accuracy of the quantum regression theorem for photon emission from a quantum dot

“…We demonstrate that the QRT systematically overestimates the phonon impact on the indistinguishability, in particular for standard GaAs QDs relevant for technological applications [39][40][41][42][43][44][45][46]. We show that this is connected to the non-Markovian part of the dynamics.…”

Chip-Scale Quantum Emitters

“…It was believed that the presented scheme is preferable to quantum dot sources directly emitting at telecom wavelengths for fiber-based quantum networking [32]. Holewa et al [33] explained the practical use of QDs in fiber-based quantum communication prepared by metal organic vapor-phase epitaxy-grown InGaAs/GaAs QDs emitting in the telecom O-band at 1.3 µm. At elevated temperatures up to at least 80 K, it was observed that the excitation of trapped holes in the vicinity of a QD leads to the formation of trion states with enhanced emissions [33].…”

“…Holewa et al [33] explained the practical use of QDs in fiber-based quantum communication prepared by metal organic vapor-phase epitaxy-grown InGaAs/GaAs QDs emitting in the telecom O-band at 1.3 µm. At elevated temperatures up to at least 80 K, it was observed that the excitation of trapped holes in the vicinity of a QD leads to the formation of trion states with enhanced emissions [33]. They concluded that the main source of luminescence quenching is related to the promotion of holes to higher states in the valence band.…”

“…(2) 50 K (0) = 0.13 up to 50 K for single-photon emission was recorded using photon autocorrelation measurements [33]. Another advance in photonic quantum technology was obtained by localization of single-photon sources in an array of 28 × 28 mesas with site-controlled InGaAs quantum dots [34].…”

Optically addressable spins in silicon carbide and related 2D materials

“…Quantum dots formed in III-V or II-VI semiconductors via self-assembly methods create trapping potentials for both electrons and holes and thus give rise to localized spins that are optically addressable [52,55,[58][59][60]. These systems may be telecom-compatible [61], but scaling them up is hindered by the large variability of quantum-dot properties [62,63]. Furthermore, III-V semiconductors are composed of elements that do not have nuclear-spin zero isotopes, and the nuclear-spin bath is an important source of decoherence for the localized electronic spins [19,20,64].…”