Entangled photon pair generation in hybrid superconductor–semiconductor quantum dot devices

Abstract

We investigate the effect of Cooper pair injection in shifting biexciton energy level of low-symmetry (C 2v ) quantum dots (QDs) exhibiting nontrivial fine structure splitting. Coupling QDs to the superconducting coherent state forms extra fine structures by intermixing the ground and biexcitonic states where spectroscopic separation of neutral exciton and biexciton can be diminished, yielding a system to be utilized in time reordering scheme. The separability of exciton and biexciton energy levels is ascribed to the corresponding direct, exchange and correlation energies calculated here through configuration interaction method. We demonstrate the possibility of enhancing photon entanglement concurrence via providing an energy coincidence for biexciton-exciton ( → ) and exciton-ground ( → 0) emissions within the weak coupling regime.

Cooper-pair-based photon entanglement without isolated emitters

“…Hybrid devices based on semiconductor-superconductor structures are a rapidly growing field [13][14][15], including QDs and nanocrystals integrated into Josephson light-emitting diodes [16,17]. These hybrid devices were proposed as enhanced QD entanglement sources [18][19][20] based on opposite-spin electrons at each discrete energy level. However, these isolated emitters have inherently low emission rates and require sophisticated fabrication methods, carrier injection, and light extraction techniques.…”

Hybrid High-Temperature-Superconductor–Semiconductor Tunnel Diode

“…A simple method of constructing high-T c tunnel junctions may create a new conceptual paradigm for tunneling-spectroscopy studies of these unconventional materials. Hybrid semiconductor-high-T c optoelectronic devices such as superconducting light sources [12,13] could help shed new light on the physics of high-T c materials by demonstrating photon-pair emission from Cooper pairs above T c , which is still a hotly debated issue [27]. The realization of such devices has been prevented, however, by the fact that high-T c epitaxial layers can be grown only on a very limited range of substrates.…”

“…A potential alternative avenue may be provided by hybrid semiconductor-superconductor devices, which have been attracting growing attention lately as they combine the controllability of semiconductor structures with the macroscopic quantum states of superconductors [5,6]. The interaction of light with semiconductor-superconductor structures has recently emerged as a new interdisciplinary field of superconducting optoelectronics, with demonstrations of light emission from hybrid light-emitting diodes [7,8] enhanced by the superconducting state [9,10], and various proposals for novel lasers [11] and quantum light sources [12,13]. These hybrid devices have also proven useful in nonlinear electronics [14,15] and infrared detection [16], taking advantage of the relatively small size of the superconducting gap in the tunneling spectrum [17].…”

Light amplification in semiconductor-superconductor structures

“…Superconducting optoelectronics, based on superconductivity in semiconductors is a rapidly growing field of research [1][2][3][4][5][6][7][8]. One of the many new fascinating phenomena related to superconductivity induced in semiconductors by the proximity effect, is enhanced light emission.…”