Quantum Information Science Group

Research

1. Quantum Sensing with Solid State Defects

Nitrogen vacancy (NV) color centers in diamond have recently drawn considerable attention as possible qubit candidates that can operate at room temperature as opposed to other leading quantum systems such as ion traps and superconducting qubits. Point defects in other wide bandgap semiconductors are also emerging as promising solid-state hosts for quantum device applications analogous to NV color centers in diamond. Paradigm shifting device functionality may be achieved if the quantum properties of point defects in this rich domain of materials are further explored. We use NV color centers in diamond and other defects in wide band-gap semiconductors for quantum sensing of extremely small physical quantities such as temperature, magnetic and electric fields.

               

NV defect confocal photoluminescence (PL)                                 DC magnetic field sensing with NV defects in 
spectra from nanodiamond at room                                                   bulk diamond crystal using the Optically 
and 10K temperatures                                                                              Detected Magnetic Resonance (ODMR) method

                 
Zero Phonon Line (ZPL) emission at 20K                                           RC series ZPL peaks were observed 
from electron beam irradiated 4H-SiC sample                                for the first time at room temperature from 
                                                                                                                                  electron beam irradiated cBN crystals

2. Electrochemically grown metallic nanowires

We use Directed Electrochemical Nanowire Assembly (DENA) method in the growth of metallic nanowires. DENA grown gold and platinum nanowires are employed in the fabrication of nanoscale voltammetry electrodes as shown in the images below.

3. Finite Difference Time Domain Simulations

We utilize Finite Difference Time Domain (FDTD) simulations to determine and optimize photonic properties of nanostructures and in designing photonic crystals and radio frequency antennas for quantum sensing applications.

FDTD simulation results of a SiC nanobeam photonic crystal with a quality factor 4.56 x 10⁴ . The electric field pattern at resonance wavelength (1540 nm) with strong confinement in the cavity region is shown in the bottom image.