DCMPMS Seminars

A charge-insensitive single-atom spin-orbit qubit in silicon

by Prof. Dimi Culcer (University of New South Wales, Australia)

Thursday, December 10, 2015 from to (Asia/Kolkata)
at AG80
Description
High-fidelity two-qubit entanglement operations pose new challenges for spin qubits. Although spin orbit-coupling (SOC) can simplify entanglement via electric fields and microwave photons, it exposes conventional spin qubits to electrical noise. Here we devise a gate-tunable single-acceptor spin-orbit qubit in silicon having a sweet spot where the electric dipole spin resonance (EDSR) is maximized, and the qubit is simultaneously insensitive to dephasing from low-frequency electrical noise. The sweet spot protects the qubit during rapid single-qubit EDSR and two-qubit dipole-dipole mediated operations, and is only obtained by treating SOC non-perturbatively. More than 10^4 one-qubit and 10^3 two-qubit operations are possible in the predicted relaxation time, as necessary for surface codes. Moreover, circuit quantum electrodynamics with single dopants is feasible in this scheme, including dispersive single-spin readout, cavity-mediated two-qubit entangement, and strong Jaynes-Cummings coupling. Our approach provides a scalable route for controlling electrical and photon-mediated interactions between spins of individual dopants in silicon.