A Four-Qubit Exchange-Only Quantum Processor On Intel's Tunnel Falls

The past few years have seen the silicon spin qubit community leverage the mature silicon fabrication infrastructure in industrial foundries for larger quantum demonstrations on more uniform and scalable devices. Furthermore, the high-throughput cryogenic characterization and advanced EUV fabrication in Intel's 300mm facilities have culminated in the rapid scaling of the number of controllable silicon spin qubits in a multi-dimensional architecture. Nonetheless, beyond device fabrication, the realization of a useful quantum computer also requires many pieces of hardware and software working in unison to preserve and manipulate fragile quantum states at scale. In this talk, we will show Intel's Tunnel Falls device operated as a 4-qubit exchange-only quantum processor, which includes high-fidelity single- and two-qubit gates, fast and high-fidelity deterministic initialization, and multi-round ancilla measurements, culminating in a demonstration of a multi-round d=2 repetition code capable of detecting bit-flip or phase-flip errors. We show that these results are extensible to larger multi-dimensional arrays, providing a strong foundation for implementing quantum error correction and demonstrating a logical qubit in silicon.