Research
Single defects in 2D materials
The solid state single photon source is a fundamental building block for application in cyber security. Recently, single photon emitters in 2D van der Waals materials have emerged as promising candidates for integrated on-chip non-classic light sources. Our research aims to deterministically fabricate single photon emitters by synthesis of 2D materials on-demand and introduction of atomic defects with electron beam irradiation and plasma.
Key papers
Advanced devices nanofabrication
Charged particle beams (CPB), of electrons or ions can be easily produced using plasmas, heated filaments or sharp wires and focused, accelerated and steered using electromagnets and electrostatic plates. Instruments such as electron and ion beam microscopes as well as a wide variety of manufacturing processes, rely upon CPB’s and have become indispensable tools for research and industry. The beam chemistry group at UTS focuses on CPB related research. The group is led by Professor Milos Toth and works with and is partially funded by Thermo-Fisher scientific, the world’s premier manufacturer of electron and ion beam based instruments.
Charged particle beams can be used to drive chemical reactions and much of the group’s work focuses upon electron and ion beam induced chemistry. Using the fine beams of electron and ion beam microscopes, this is useful for 3D printing and engraving at the nanoscale. This capability has significant potential in next-generation nanofabrication. Apart from beam induced chemistry, research is performed with CPB based analytical techniques such as cathodoluminescence spectroscopy and energy dispersive X-ray spectroscopy. Significant research effort is also devoted to development of new techniques and tools that will be useful in next generation electron/ ion beam microscopy and nanofabrication.
Key papers
- Role of knock-on in electron beam induced etching of diamond
- Versatile direct-writing of dopants in a solid state host through recoil implantation
- Bottom up engineering of single crystal diamond membranes with germanium vacancy color centers
- Single Crystal Diamond Membranes and Photonic Resonators Containing Germanium Vacancy Color Centers
Integrated nanophotonics
Implementation of quantum networks and photonic processors require interfacing multiple single photons on a chip. For this purpose, efficient integration of quantum light sources and photonic resonators, such as waveguides and cavities, is necessary. To this end, photonic integrated quantum circuits have become an attractive research direction that is poised to deliver compact yet complex solid-state photonic quantum circuitry.
A promising approach for integrated scalable quantum systems is the use of emerging single-photon emitters in 2D materials. Due to the 2D nature of the host, they can be transferred onto photonic structures via exfoliation and stamping, reproducibly and in ambient conditions. Our group is pioneering researches on the integration of 2D materials with photonic devices.
Key papers
- Quasi-BIC Resonant Enhancement of Second-Harmonic Generation in WS2 Monolayers
- A Single Chiral Nanoparticle Induced Valley Polarization Enhancement
- Strain‐Induced Modification of the Optical Characteristics of Quantum Emitters in Hexagonal Boron Nitride
- Photonic crystal cavities from hexagonal boron nitride
Quantum sensing
Quantum sensing is an emerging sub-field of quantum physics whereby the sensitivity and/or spatial resolution exceeds what can be achieved with classical physics by orders of magnitude. In quantum sensing, a single quantum system is exploited to sense external stimuli, including electric field, magnetic field, and temperature. Our research aims to use individual color centers in wide-bandgap semiconductors such as hexagonal boron nitride and diamond as quantum sensors for reading-out and mapping of external stimuli at the nanoscale limit.
Key papers
