Cryogenic III-V and Nb electronics integrated on silicon for large-scale quantum computing platforms.

Quantum computers now encounter the significant challenge of scalability, similar to the issue that classical computing faced previously. Recent results in high-fidelity spin qubits manufactured with a Si CMOS technology, along with demonstrations that cryogenic CMOS-based control/readout electronics can be integrated into the same chip or die, opens up an opportunity to break out the challenges of qubit size, I/O, and integrability. However, the power consumption of cryogenic CMOS-based control/readout electronics cannot support thousands or millions of qubits. Here, we show that III-V two-dimensional electron gas and Nb superconductor-based cryogenic electronics can be integrated with Si and operate at extremely low power levels, enabling the control and readout for millions of qubits. Our devices offer a unity gain cutoff frequency of 601 GHz, a unity power gain cutoff frequency of 593 GHz, and a low noise indication factor of at 4 K using more than 10 times less power consumption than CMOS.