« Cryogenic Electronics for Quantum Computing: Carrier Transport in Cryo-CMOS »

Professor Ken Uchida
from the University of Tokyo

 12/11/2026
10h – IEMN Laboratoire Central -Salle du conseil

Abstract:

Quantum computers have the potential to revolutionize computing in fields such as materials science, drug discovery, and optimization. However, scaling up quantum computers requires energy-efficient electronic circuits for controlling and reading out large numbers of qubits. Cryogenic CMOS (Cryo-CMOS) technology offers a promising solution by integrating control electronics into cryogenic environments.
This talk reviews the opportunities and challenges of Cryo-CMOS technologies, focusing on transistor operation at extremely low temperatures. Particular attention is given to carrier freeze-out, hopping conduction, and slow dopant ionization, which significantly influence transistor characteristics. We present experimental investigations and physical models of carrier transport in cryogenic silicon devices, including variable-range hopping, frequency-dependent substrate impedance, and transient transistor behavior. The importance of hopping transport in the subthreshold region is also discussed. Furthermore, we address practical challenges associated with self-heating and noise in cryogenic circuits. These findings provide insights into the fundamental physics of semiconductor devices at cryogenic temperatures and contribute to the development of reliable, energy-efficient Cryo-CMOS technologies for scalable quantum computing systems.

Short CV of Prof. Ken Uchida :
Ph.D. in Engineering, University of Tokyo, 2002.
Visiting Scientist, Stanford University (on leave from Toshiba), 2003–2005.
Associate Professor, Department of Physical Electronics, Tokyo Institute of Technology, 2008.
Professor, Department of Electronics and Electrical Engineering, Keio University, 2012.
Professor, Department of Materials Engineering, University of Tokyo, 2018.
Prof. Ken Uchida is an internationally renowned researcher in nanoscale electronic devices, transport phenomena in nanomaterials, and molecular sensing. He has served for several years on the programme committees of the IEEE International Electron Devices Meeting (IEDM), the Symposium on VLSI Technology, and the European Solid-State Device Research Conference (ESSDERC). More recently, he has expanded his research to include cryogenic electronics.