Quantum Computing
Device scaling of CMOS may not continue after so much great success in the past six decades. For future computing technologies, quantum computing is the most promising candidate owing to its ultimate computing power compared to classical computing. Among all candidates, solid-state systems such as spin qubits and superconducting transmon qubits have attracted much attention because of scalability and compatibility to Si-based CMOS VLSI technology. Our group is aiming for the development of large-scale qubit system integrated with the cryo-CMOS devices by working on (i) material growth of Si/SiGe, Ge/GeSi, and GeSn/Ge heterostructures, (ii) device fabrication of quantum dots and Josephson junctions devices, (iii) spin manipulation by electron-spin resonance (ESR), electric-dipole spin resonance (EDSR), or spin-orbit coupling (SOC), and (iv) cryogenic characterizationof qubit devices (~ 20 mK) and cryo-CMOS (1.5 K).