Carrier flow and nonequilibrium superconductivity in superconductor-based LEDs.

Transport properties of superconductor-based LEDs are quantitatively investigated. In the gate-controlled region, we confirm the realization of a new type of Josephson field effect transistor performance, in which the channel cross-sectional area of the junction can be directly modulated by the gate voltage. In the current-injected region, a superconducting critical current of the order of a few microamperes is found to be modulated by the steady current injection of the order of a few picoamperes. This ultrahigh monitoring sensitivity is considered to be due to the large energy mismatch between generated photons and superconducting pairs in the radiative recombination process, which causes the carrier flows and nonequilibrium superconductivity in the active layer. [ABSTRACT FROM AUTHOR]