Detection of Coherent Terahertz Radiation from a High-Temperature Superconductor Josephson Junction by a Semiconductor Quantum-Dot Detector

Abstract

We examine the application of Josephson radiation emitters to spectral calibration of single-photonresolving detectors. Josephson junctions are patterned in a YBCO film on a bicrystal sapphire substrate and are voltage controlled to generate radiation in the frequency range of 0.05-1 THz. The detector used in this work consists of a gate-defined quantum-dot photon-to-charge transducer coupled to a single-electron transistor. Both the emitter and the detector are equipped with a matching on-chip wide-band antenna. The combination of a tuneable emitter and detector allows us to determine the efficacy of the YBCO emitter and also to analyze the elementary processes involved in the detection.

Graphene Quantum Dot Crystal Serving as a Multi‐Qubit Circuit Operating at High Temperatures

“…In the latter case, the qubit circuit retains functionality provided it operates at higher gate switching frequency f ≈ 100 GHz, which would be possible when using graphene field effect transistor (FET). [52] Recent papers [27][28][29][30][31] describe experiments on electron transport in the carbon nanotube and semiconducting heterostructure quantum dot structures exposed to a.c. fields in the terahertz frequency range. In ref.…”

“…Recent papers [ 27–31 ] describe experiments on electron transport in the carbon nanotube and semiconducting heterostructure quantum dot structures exposed to a.c. fields in the terahertz frequency range. In ref.…”

“…In ref. [27], the authors report detecting the radiation in the frequency range of 0.05–1 THz with a gate‐defined quantum‐dot photon‐to‐charge transducer coupled to a single‐electron transistor. Highly doped Si 40 nm‐diameter quantum dots with a micrometer‐scale broadband logarithmic spiral antenna have been implemented in ref.…”

“…[31]. The results [ 27–31 ] show that the gate‐defined quantum dots successfully operate at THz frequencies and might have a promising potential for practical applications in multi‐qubit circuits.…”

THz Properties of Long YBaCuO Bicrystal Josephson Junction Studied with a Cold-Electron Bolometer

“…Josephson generators are one of the most convenient sources of GHz and subTHz signals because they have the potential to generate in a wide frequency range, and their main frequency is easily determined by the Josephson relation. Measurement of high-temperature JJs, both YBa 2 Cu 3 O 7−δ and Bi 2 Sr 2 CaCu 2 O 8 , requires the use of very sensitive detectors, such as integrated superconducting heterodyne receivers [17][18][19], bolometers [20,21], single-photon detectors [22]. For the analysis of planar bicrystal junctions in all works short junctions were used.…”