ESE Seminar: “Engineering Quantum Processors in Silicon”
February 27 at 11:00 AM - 12:00 PM
Across the globe, physicists in academia and industry alike are competing to be the first to build a scalable universal quantum computer. Amongst the multitudes of quantum computing architectures, solid-state quantum processors based on spins in silicon are emerging as a strong contender. Silicon is an ideal material to host spin qubits: it supports long coherence times , has excellent prospects for scaling, and is ubiquitous in the semiconductor industry. While semiconductor spin qubits were proposed over two decades ago , it is only within the past few years that we have learned how to fabricate and control multi-qubit devices in silicon.
In this seminar, I will describe our state-of-the-art four-qubit Si/SiGe quantum dot device  and explain how we have overcome major barriers to realizing large-scale quantum computing in silicon. First, I will discuss charge control and spin-state readout in the device. Then, I will describe the use of an on-chip micromagnet to mediate electrically driven spin resonance [4-5]. Using this technique, we achieve site-selective spin control with fidelities exceeding 99.9%. I will outline the operation of our three primitive two-qubit gates: the decoupled-CZ gate , the resonant CNOT gate , and the resonant SWAP gate . Finally, I will discuss how these advances enable the development of large-scale quantum processors capable of complex quantum information processing.
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Associate Research Scholar of Physics, Princeton University
Anthony Sigillito is currently a Dicke Postdoctoral Fellow in the Department of Physics at Princeton University. In this role, he has been working with Professor Jason Petta to develop Si/SiGe-based quantum dot devices for quantum information processing applications. More specifically, Anthony has fabricated the first four-qubit quantum processor in silicon and demonstrated the first entangling CNOT gate in Si/SiGe devices.
Prior to joining the Physics department, Anthony completed his Ph.D. with Professor Steve Lyon as a Gordon Y.S. Wu fellow in the Department of Electrical Engineering at Princeton. His Ph.D. work focused on studying donor electron and nuclear spin dynamics in silicon and germanium using superconducting electron spin resonance devices. His research explored the physical processes that couple electron and nuclear spins to electric fields and led to the first demonstration of all-electrical nuclear spin control in silicon.