Carrier flow and nonequilibrium superconductivity in superconductor-based LEDs

Abstract

Superconductor-based light-emitting diode (superconductor-based LED) in strong lightconfinement regime are characterized as a superconductor-based three-terminal device, and its transport properties are quantitatively investigated. In the gate-controlled region, we confirm the realization of new-type Josephson field effect transistor (JoFET) performance, where the channel cross-sectional area of the junction is directly modulated by the gate voltage. In the current-injected region, the superconducting critical current of µA order in the Josephson junction is found to be modulated by the steady current injection of pA order. This ultrahigh monitoring sensitivity of the radiative recombination process can be explained by taking into account the fact that the energy relaxation of the absorbed photons causes the conversion of superconducting pairs to quasiparticles in the active layer. Using quasiparticle density and superconducting pair density, we discuss the carrier flows together with the non-equilibrium superconductovity in the active layer and the superconducting electrodes, which take place for compensating the conversion.

Semiconductor–superconductor optoelectronic devices

“…Since superconductivity is based on electron Cooper-pairs [2], hybrid structures combining superconductors with semiconductors (such as the p-n junction) can exhibit much stronger two-photon emission based on second-order light-matter interaction involving Cooper-pairs. Such second-order lightmatter interactions in semiconductor-superconductor structures have been shown, both theoretically [17] (equation (5)) and experimentally [16,[30][31][32] to be the underlying physical effect behind enhanced luminescence obtained in superconducting LEDs (SLEDs) at temperatures lower than T c .…”

“…The first type of SLED structure with only n-type side of the p-n junction connected to a superconductor contact, has been implemented and thoroughly explored [16,[30][31][32]. The typical structure is composed of a p-n junction with two superconducting contacts placed on top of the n-type layer (figure 3(a)).…”

Andreev Reflection in a Superconducting Light-Emitting Diode

“…Hybrid superconductor−semiconductor devices are a rapidly growing field of research, with a wide range of applications, including a variety of quantum devices, − such as quantum dot (QD) based light-emitting diodes (LEDs), − Bell-state analyzers, and superconducting two-photon amplifiers . One of the most promising directions in these hybrid devices is generation of entangled-photon pairs through Cooper-pair luminescence in compact semiconductor devices, crucial for practical quantum technologies.…”