Quantum-Dot Single-Electron Transistors as Thermoelectric Quantum Detectors at Terahertz Frequencies

Low-dimensional nanosystems are promising candidates for manipulating, controlling, and capturing photons with large sensitivities and low noise. If quantum engineered to tailor the energy of the localized electrons across the desired frequency range, they can allow devising of efficient quantum sensors across any frequency domain. Here, we exploit the rich few-electron physics to develop millimeter-wave nanodetectors employing as a sensing element an InAs/InAs0.3P0.7 quantum-dot nanowire, embedded in a singleelectron transistor. Once irradiated with light, the deeply localized quantum element exhibits an extra electromotive force driven by the photothermoelectric effect, which is exploited to efficiently sense radiation at 0.6 THz with a noise equivalent power <8 pWHz(-1/2) and almost zero dark current. The achieved results open intriguing perspectives for quantum key distributions, quantum communications, and quantum cryptography at terahertz frequencies.

Automated summary

Low-dimensional nanosystems show promise in manipulating and controlling photons with large sensitivities, and by quantum engineering tailored energy levels of localized electrons can result in efficient quantum sensors. Utilizing few-electron physics, millimeter-wave nanodetectors have been developed to efficiently sense radiation at 0.6 THz with low noise levels, opening up prospects for quantum communications and cryptography.