Scaling up semiconductor spin qubits

In this talk, I will present our vision of a large-scale spin-based quantum processor, and ongoing work to realize this vision. First, we create local registers of increasing numbers of spin qubits in quantum dot arrays with sufficient control that we can program arbitrary sequences of operations. Furthermore, in close collaboration with Intel, we have measured quantum dot qubits fabricated using all-optical lithography and industrial process technology on a 300 mm wafer. This industrial approach to nanofabrication will be critical for achieving the extremely high yield necessary for devices containing hundreds or thousands of qubits. Second, we explore the coherent coupling of spin qubits at a distance via two routes. In the first approach, the electron spins remain in place and are coupled via a superconducting resonator. In the second approach, spins are shuttled along a quantum dot array, preserving both the spin projection and spin phase. Third, we work towards the integration of quantum bits and classical electronics on the same chip or package, where qubits are operated above 1 K and the electronics is designed for cryogenic operation. When combined, the progress along these various fronts can lead the way to scalable networks of high-fidelity spin qubit registers for computation and simulation.