Talk: Dogs and cats, living together! How approaches to Josephson junction and spin-based quantum computing can learn from each other

I will talk about two of our recent proposals for quantum computers based on superconducting JJ circuits [1] and spins in semiconductors [2]: what motivated them, why they are worth pursuing experimentally, and directions for future research.

[1] Semiconductor-inspired design principles for superconducting quantum computing, Nature Communications 7, 11059 (2016)

[2] Charge-noise-insensitive gate operations for always-on, exchange-only qubits, Phys. Rev. B 93, 121410(R) (2016)

Lincoln Laboratory, Boston, MA




Talk: Silicon Quantum Information Technology

Information technology based on the fundamental nature of the universe, namely quantum physics, can in some cases dramatically outperform the best “classical” solution. In other words, a quantum computer will be important someday. But the challenges are still immense. Somewhat surprisingly, silicon may continue to be an exceptionally relevant material even into a future era of quantum-enhanced technology. Here I will discuss progress in silicon quantum computing and related semiconductor-based devices touching on my own research interests and highlighting experimental results across the community.

GOMACTech, Orlando, FL



Talk: A new look at encoded-qubit quantum dot quantum computing in silicon

Although the properties of spin-based qubits are specified by the material system they reside in, it’s possible to modify those properties by encoding a qubit into multiple physical spins. Here we consider new operating regimes for encoded spin qubits and discuss their relevance to spin-based quantum computing and qubit-qubit coupling, especially in silicon quantum dot systems. We will also briefly discuss recent developments in g-factor theory in silicon quantum dots and their possible implications.

We introduce an always-on, exchange-only qubit made up of three localized semiconductor spins that offers a true “sweet spot” to fluctuations of the quantum dot energy levels. Both single- and two-qubit gate operations can be performed using only exchange pulses while maintaining this sweet spot. We show how to interconvert this qubit to other three-spin encoded qubits as a new resource for quantum computation and communication.

APS March Meeting, Baltimore, MD

A new look at encoded-qubit quantum dot quantum computing in silicon






Charles Tahan
Physicist in Washington, D.C.