Quantum State Discrimination in Cryogenic Environment

Large-scale quantum computers require high-fidelity control and readout of a large number of qubits, residing at millikelvin temperatures, resulting in a massive input–output bottleneck. Current qubits are mainly controlled by classical hardware at room temperature, which cannot be scaled efficiently and has limited control capabilities. To overcome quantum computing’s scalability challenges the control hardware needs to be closely integrated with the qubits to enable systematic control for modular scalability. A promising solution is to develop cryogenic control based on superconducting computing with logic families, such as eSFQ and AQFP. The primary advantage of superconducting classical computing over cryo-CMOS and CMOS technologies is power efficiency and computation speed of at least 50GHz. Moreover, in the noisy intermediate scale quantum (NISQ) era, we need fast and energy-efficient classical computers tightly coupled with the Quantum processor to implement algorithms such as variational quantum eigensolver (VQE) or even quantum error correction (QEC). We will present our progress in developing a superconducting co-processing unit capable of performing qubit manipulation and optimization, readout, and classical computation for large-scale quantum computers.