Superconducting Integrated Circuits for Scalable Quantum Systems

Superconducting circuits based on Josephson junctions (JJs) are the cornerstone of quantum and classical cryogenic electronics, which is an active topic of research and technological development. Conventional JJs rely on electric current or magnetic flux control, which is far less practical as compared to the voltage control used in conventional field-effect transistors underpinning the modern semiconductor industry. Thus, the realisation of scalable gated JJs with local electrostatic control - Josephson field-effect transistors (JoFETs) - is expected to kick off a new era in quantum computing hardware and ultra-fast and low-power computing in the fields of artificial intelligence (AI) and high-performance computing (HPC). Moreover, JoFET technology can provide ultra-low-power superconducting integrated circuits (ICs) for qubit control and readout, unachievable by conventional silicon electronics, to support and enable the ongoing quantum computing revolution.Despite the proof-of-concept demonstrators of JoFETs in various material platforms, reported since the 1980s, the technology has not advanced to the IC level. Empowered by the unique scalable fabrication process for graphene-based JoFETs recently demonstrated by SuperICQ members, we will develop a 200 mm wafer platform for truly scalable superconducting JoFET integrated circuits. With our platform, individual modules will be developed, such as quantum-limited parametric amplifiers, on-chip filters, ultra-sensitive microwave bolometers, voltage-tunable resonators, and multiplexed control and readout modules for scalable interfacing of superconducting qubits. We will validate the developed JoFET ICs by using them for the control and readout of state-of-the-art superconducting qubits. Our project’s ultimate goal is to demonstrate a novel path toward ultra-low-power electronics for scalable control, readout, and interfacing of superconducting quantum computers and advance toward future quantum systems-on-a-chip.