CQE Seminar: Matthew Rakher, HRL

Encoded Silicon Qubits: A High-Performance & Scalable Platform for Quantum Computing

Abstract: For quantum computers to achieve their promise, regardless of the qubit technology, significant improvements to both performance and scale are required.  Quantum-dot-based qubits in silicon have recently enjoyed dramatic advances in fabrication and control techniques.  The “exchange-only” modality is of particular interest, as it avoids control elements that are difficult to scale such as microwave fields, photonics, or ferromagnetic gradients.  In this control scheme, the entirety of quantum computation may be performed using only asynchronous, baseband voltage pulses on straightforwardly tiled arrays of quantum dots.  The pulses control only a single physical mechanism, the exchange interaction, which exhibits low control crosstalk and exceptionally high on/off ratios.  Exchange enables universal logic within a qubit encoding that is robust against certain correlated errors.  These aspects collectively provide a compelling path toward fault-tolerance.  HRL Laboratories has recently demonstrated universal quantum logic of encoded exchange-only Si spin qubits, including two-qubit gates performed on arrays of six quantum dots.  In this seminar/colloquium/talk/video, we will introduce the fabrication and operation principles of these encoded Si qubit devices, and we will show recent experimental results.

How to attend: To attend virtually, email quantum@uchicago.edu to request the Zoom link. 

This event is only open to CQE Members, Partners and Trainees. 

This convening is open to all invitees who are compliant with UChicago vaccination requirements and, because of ongoing health risks, particularly to the unvaccinated, participants are expected to adopt the risk mitigation measures (masking and social distancing, etc.) appropriate to their vaccination status as advised by public health officials or to their individual vulnerabilities as advised by a medical professional. Public convening may not be safe for all and carries a risk for contracting COVID-19, particularly for those unvaccinated. Participants will not know the vaccination status of others and should follow appropriate risk mitigation measures.