Cryo-CMOS Interfaces for Large-Scale Quantum Computers

Summary form only given, as follows. The complete presentation was not made available for publication as part of the conference proceedings. Quantum computers hold the promise to solve problems that are intractable even for the most powerful supercomputers. They operate by processing information stored in quantum bits (qubits), which must typically be cooled down to cryogenic temperatures. Today the qubits are controlled by conventional electronics working at room temperature. This thermal gap can be readily bridged by a few wires since today’s quantum computers employ only a few qubits. However, practical quantum computers will require more than thousands of qubits, making this approach impractical. An alternative approach is to build an electronic interface that can operate at cryogenic instead of room temperature, so that it can easily be connected to many qubits. Focusing on the use of standard CMOS technology, we will explore the challenges in building such interface, comprising modelling of the quantum/classical interface, devices modelling for cryogenic CMOS (cryo-CMOS), and the design of high-performance cryogenic CMOS circuits. We will demonstrate the cryogenic operation of complex CMOS analog and digital systems, including the 22-nm CMOS Horse Ridge, the most complex cryo-CMOS circuit ever demonstrated and able to drive up to 128 frequency-multiplexed spin qubits or transmons, thus showing that cryogenic CMOS is a viable technology to enable large-scale quantum computing.