Available on-demand - *F.NM05.06.01
Quantum Computing with Semiconductors—Spins Inside
Quantum computation has captivated the minds of many for almost two decades. For much of that time, it was seen mostly as an extremely interesting scientific problem. In the last few years, we have entered a new phase as the belief has grown that a large-scale quantum computer can actually be built. Quantum bits encoded in the spin state of individual electrons in silicon quantum dot arrays, have emerged as a highly promising direction . 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 created local registers of spin qubits with sufficient control that we can program arbitrary sequences of operations. We show the creation of each of the Bell states with fidelities of 85-90% and the implementation of the four instances of the Deutsch-Jozsa and the Grover algorithms on two qubits .
Second, we have explored coherent coupling of spin qubits at a distance via two routes. In the first approach, the electron spins remain in place and our coupled via an intermediary degree of freedom. After showing this principle with an ancillary quantum dot as a coupler , we recently observed strong coupling of a single spin to a single microwave photon in a superconducting resonator . In the second approach, spins are shuttled along a quantum dot array, preserving both the spin projection  and spin phase .
Third, in close collaboration with Intel, we have fabricated and measured quantum dots using all-optical lithography on 300 mm wafer, using industry-standard processing . Qubit measurements are now underway. We expect that this industrial approach to nanofabrication will be critical for achieving the extremely high yield necessary for devices containing hundreds or thousands of qubits. Furthermore, we anticipate that the device stability and charge noise levels will eventually outperform those of devices made in university-style cleanrooms.
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.
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