The Physics & Astronomy Colloquium Series presents Mark A. Eriksson, Department Chair and John Bardeen Professor of Physics from University of Wisconsin-Madison, discussing "Quantum Computing using Electron Spins in Silicon" on Sept. 22.

Abstract: Remarkably, the techniques used to make classical silicon CMOS devices can be used to make qubits with excellent performance.  The operation of these devices, on the other hand – from the required temperatures to the number of electrons comprising a typical qubit – is very different from what is found in even the most advanced classical integrated circuits. 

In this talk I will present both a short historical overview of how quantum computing in silicon has developed, as well as the latest results from both our group at Wisconsin and from around the world.  I will emphasize the role of integration, including 3D integration, which enables readout of qubits formed in a Si/SiGe by measuring the microwave transmission of a superconducting resonator on a separate substrate, flip-chip bonded to the first.  And I will discuss very recent results demonstrating the remarkable properties of silicon quantum wells containing short wavelength oscillations in the concentration of added germanium atoms.  Advances like these have, in just the last few years, demonstrated that a future quantum computing technology in silicon will likely integrate sophisticated techniques and knowledge cutting across many difference academic departments, from electrical engineering to materials science, computer science, and physics – a feature that makes it an incredibly dynamic (and fun!) field of science and technology.