Damien Kemna

Major: Physics
Mentors: Casey Kim, Carl Padgett, Dr. Jayameenakshi Venkatraman, Professor Ania Jayich

Towards High-Fidelity Readout of a Spin Ensemble with a Superconducting Circuit

Nitrogen Vacancy (NV) center defects in diamond are highly sensitive to minuscule magnetic fields, making them powerful quantum sensors. One challenge associated with using a quantum sensor is reading out the information encoded in the sensor. An effective quantum sensor readout maximizes information while minimally adding noise. The conventional method of NV ensemble readout utilizes laser excitation and optical readout, but this method introduces added noise in the form of photon shot noise, leading to poor fidelity. Here we pursue an alternative readout mechanism that utilizes microwave-frequency superconducting circuits to improve fidelity through increased photon collection efficiency and time at millikelvin temperatures. We demonstrate the preparation and fabrication of a ~5 GHz superconducting circuit with high quality factor and large inductive coupling to a NV ensemble. We discuss the prospects of using this circuit with a quantum limited amplifier as an alternative method of high-fidelity readout of a NV ensemble.