Alexander Crook’s PhD Thesis Defense

3:00–4:00 pm

Please join us:

Alexander Crook’s PhD Thesis Defense

Thursday, July 22, 2021, 3:00 pm CDT

PHOTONIC ENHANCEMENT OF SPIN QUBITS IN SILICON CARBIDE

The emergence of controllable quantum systems has led to exciting applications for quantum computation, communication, and metrology. Among the many candidate systems, silicon carbide has attracted interest as a solid-state quantum platform in a technologically mature semiconductor material. When one creates atomic defects in silicon carbide lattice, individual electrons become trapped in isolated energy levels in the band gap. These electron spins can then be optically initialized and read out while being coherently controlled through microwave frequency fields. This interface between spin and photon quantum states provides exciting opportunities for creating remote entanglement on a macroscopic length scale.

In this talk, I will outline the foundations of the divacancy in silicon carbide as a spin qubit. Then I will discuss the fabrication of nanoscale photonic crystal cavities in silicon carbide in order to modify the divacancy's optical emission. A combination of electron-beam lithography and photoelectrochemical etching is employed to create suspended nanocavities. Using these structures, we observe a substantial Purcell enhancement of the divacancy zero-phonon line and a reduced excited state lifetime. Additionally, we demonstrate spin control and coherence in these devices for the first time. More broadly, the cavity-emitter interactions in this system allow us to study transduction between spin and photonic degrees of freedom and provide a first step towards next generation hybrid devices.

Committee members:

David Awschalom (Chair)

Aashish Clerk

David Schuster

Sidney Nagel

Alex will continue as a postdoc in the Awschalom lab. 

Event Type

Thesis Defense

Jul 22