Remote coupling of quantum dot spin qubits via a superconducting qubit coupler

Gate-defined quantum dots represent a promising candidate for a scalable qubit platform.  A key advantage of quantum dots is their small physical footprint, which could enable the integration of many millions of qubits on a single chip. However, this high qubit density creates challenges in routing the on-chip classical control signals needed to scale these systems to a size capable of solving problems of real-world relevance. To address this, long-range spin coupling mechanisms are needed to connect spatially sparse arrays of spin qubits. We propose a novel coupling scheme in which a superconducting qubit mediates interactions between distant quantum dot spin qubits. To implement this approach, we have developed a hybrid semiconductor–superconductor measurement architecture, drawing on established engineering practices from the superconducting qubit community. In this talk, we will present characterization measurements of both the superconducting and quantum dot qubits within this hybrid platform. We will also discuss our progress toward 3D integration of the two qubit types via flip-chip bonding, a key milestone toward realizing hybrid quantum devices.