Self‐Assembled InAs/GaAs Coupled Quantum Dots for Photonic Quantum Technologies

Abstract

Coupled quantum dots (CQDs) that consist of two InAs QDs stacked along the growth direction and separated by a relatively thin tunnel barrier have been the focus of extensive research efforts. The expansion of available states enabled by the formation of delocalized molecular wavefunctions in these systems has led to significant enhancement of the already substantial capabilities of single QD systems and have proven to be a fertile platform for studying light–matter interactions, from semi‐classical to purely quantum phenomena. Observations unique to CQDs, including tunable g‐factors and radiative lifetimes, in situ control of exchange interactions, coherent phonon effects, manipulation of multiple spins, and nondestructive spin readout, along with possibilities such as quantum‐to‐quantum transduction with error correction and multipartite entanglement, open new and exciting opportunities for CQD‐based photonic quantum technologies. This review is focused on recent CQD work, highlighting aspects where CQDs provide a unique advantage and with an emphasis on results relevant to photonic quantum technologies.

Photonic Quantum Technologies

“…[16] -Recent work in the field of self-assembled InAs/GaAs coupled quantum dots (CQDs) is reviewed. [17] The work focuses on highlighting aspects where CQDs provide a unique advantage with an emphasis on results relevant to photonic quantum technologies. -New experiments using tip-enhanced strong coupling to optimize the coupling strength between a plasmonic cavity and a single quantum emitter is described.…”

Defect-Free Axially Stacked GaAs/GaAsP Nanowire Quantum Dots with Strong Carrier Confinement

“… 3 Enhanced complexity can be achived by closely stacking two or more QDs to achieve coupling/wave function entanglement. 4 − 6 These QD molecular systems have been proposed as novel electromagnetic resonators, quantum gates for quantum computing, and thermoelectric energy harvestors. 7 − 10 …”

“… 11 However, the resulting strain field makes the growth of high-quality vertically stacked identical QDs very challenging. 6 Horizontally coupled QD pairs in thin-film structures have been studied, but the center-to-center distance between two dots is large (>30 nm), resulting in significantly weaker coupling compared with the few nanometers of separation of vertically stacked QDs. 9 Self-assembled QDs have a number of other significant disadvantages, including formation at random positions, large inhomogeneous size distributions, limited shape and size control, and restrictions on which semiconductors can be combined in a single structure.…”

Single Photon Emitters Coupled to Plasmonic Waveguides: A Review

“…[5] Therefore, solid-state emitters with atom like emission properties are considered to be promising for integrated quantum optics. [6][7][8][9][10][11][12] Solid-state emitters also have issues such as their emission in all directions, and low emission rate which make it challenging for their use in quantum technologies. Emission properties of an emitter can be modified by engineering the environment of an emitter.…”