Semiconductor quantum dots as an ideal source of polarization-entangled photon pairs on-demand: a review

Abstract

More than 80 years passed since the first publication on entangled quantum states. In this period of time the concept of spookily interacting quantum states became an emerging field of science. After various experiments proving the existence of such non-classical states, visionary ideas were put forward to exploit entanglement in quantum information science and technology. These novel concepts have not yet come out of the experimental stage, mostly because of the lack of suitable, deterministic sources of entangled quantum states. Among many systems under investigation, semiconductor quantum dots are particularly appealing emitters of on-demand, single polarization-entangled photon-pairs. Although, it was originally believed that quantum dots must exhibit a limited degree of entanglement related to numerous decoherence effects present in the solid-state. Recent studies invalidated the premise of unavoidable entanglement degrading effects. We review the relevant experiments which have led to these important discoveries and discuss the remaining challenges for the anticipated quantum technologies.

Distinctive characteristics of carrier-phonon interactions in optically driven semiconductor quantum dots

“…While QDs are interesting objects for studying the fundamentals of the carrier-phonon interaction on the nano-scale, they are likewise highly attractive candidates for applications in quantum information technology. In particular, QDs could be used as single [48][49][50][51][52][53][54][55] or pair photon sources [54,[56][57][58][59][60][61][62][63] or in quantum networks [64]. Therefore it is also of high interest to understand the impact of the carrier-phonon interaction on the properties of the photons emitted from a QD.…”

Quantum hydrodynamics of a single particle

“…We thus decided to use single QDs as a deterministic single-photon source with an emission linewidth compatible with the narrow polariton resonance. However, most common QD ; The antibunching value of g (2) (0) = 0.16 ± 0.05 is an unequivocal signature of single-photon emission from these QDs systems (e.g., InGaAs QDs grown with the Stranski-Krastanow method) have a typical emission range incompatible with GaAs/AlGaAs microcavities. We use therefore GaAs QDs produced by Al droplet etching, which have been recently shown to be nearly ideal single photon sources 32 with g (2) (τ = 0) below 10 −4 .…”

“…IO chips should provide qubit generation, processing and readout. For instance, qubit generation can be implemented by using semiconductor quantum dots (QDs) 2,3 or parametric sources 4,5 . Superconducting single-photon detectors 6 seem to be among the most promising candidates to date for integrated qubit detection 7,8 .…”

Fabrication of In(P)As Quantum Dots by Interdiffusion of P and As on InP(311)B Substrate

“…Semiconductor quantum dots (QDs) have attracted much attention because they can confine electrons and holes three dimensionally. Therefore, QDs were expected to be used in high performance semiconductor lasers and to be applied in quantum information and communication technologies [1][2][3][4][5]. The technique for self-assembling QDs is widely used for application to optical devices (such as semiconductor laser diodes) using the Stranski-Krastanow (S-K) growth mode because these applications do not require control of a QD position.…”