HIRAKAWA GROUP [Quantum Nanophysics and its Device Applica@ons] Nanoscience Center for Photonics, Electronics, and Materials Engineering Quantum Semiconductor Electronics Terahertz photodynamics and device applications of quantum nanostructures Ee202 Department of Electronic Engineering and Informa@on Systems hLp://thz.iis.u-tokyo.ac.jp Quantum nanophysics and its device applica3ons Various intriguing physics shows up in quantum nanostructures owing to size quan@za@on and electron-electron interac@on effects. We inves@gate novel physics in such quantum nanostructures and explore their device applica@ons. ■ Carrier dynamics and device applica@ons of quantum nanostructures in the THz range ■ Nanoscience for single molecular transistors ■ Novel high-sensi@vity, fast terahertz detectors using MEMS resonators ■ Thermionic cooling effect in semiconductor heterostructures Bloch oscillation in semiconductor superlattices and its application to THz oscillators Fabrication of atomic-scale nanogap electrodes and single molecular transistors Thermionic cooling in semiconductor heterostructures -1 0 1 2 3 4 Time (psec) T = 10K THz electric field, E THz (arb. units) 1 11 21 31 F b = 39 kV/cm GaAs (6.5 nm)/Al 0.3 Ga 0.7 As (2.5 nm) SL femtosecond laser V G (V) V SD (mV) C84 Drain Source Gate 20 30 40 Time (s) G J (2e 2 /h) 0.3 0.4 0.5 0.6 V J (V) V J 100 s G J Au V C -100 -50 0 50 100 -20 -15 -10 -5 V G (V) V SD (mV) N N-1 Sample A 1 nm Development of uncooled, high-sensitivity terahertz detectors using MEMS resonators NiCr 120μm Au AuGeNi PE VOx MEMS (pyroelectric) NEDT~1 mK/√Hz NEDT~1 μK/√Hz -35 -30 -25 -20 -15 -10 -5 0 Δf (kHz) V o (x) (mV) 0 μW 390 μW 800 μW 640 μW 500 μW 200 μW