A photonic link for donor spin qubits in silicon

Date: 
Wednesday, April 19, 2017 - 4:00pm
Speaker: 
Stephanie Simmons
Speaker's Institution: 
Simon Fraser University

Atomically identical donor spin qubits in silicon offer excellent native
quantum properties, which match or outperform many qubit rivals. To scale up
such systems it would be advantageous to connect silicon donor spin qubits
in a cavity-QED architecture. Many proposals in this direction introduce
strong electric dipole interactions to the otherwise largely isolated spin
qubit ground state in order to couple to superconducting cavities. Here I
present an alternative approach, which uses the built-in strong electric
dipole (optical) transitions of singly-ionized double donors in silicon.
These donors, such as chalcogen donors S^$+$, Se^$+$ and Te^$+$, have the same
ground-state spin Hamiltonians as shallow donors yet offer mid-gap binding
energies and mid-IR optical access to excited orbital states. This photonic
link is spin-selective which could be harnessed to measure and couple donor
qubits using photonic cavity-QED at 4.2K. I will present preliminary
data in support of this approach, including 4.2K optical initialization/readout
in Earth's magnetic field, where long T1 and T2 times have been measured.