Seminar on making artificial electronic materials by Dr. Oleh Klochan
The electronic properties of materials are determined by the atomic constituents and their crystal lattice structure. Engineered electronic materials, which are created by applying a designed spatially periodic potential, a superlattice, have offered a powerful way to alter the properties of natural crystals in a controlled manner. For example, Moire superlattices, where different layers of two-dimensional (2D) materials are stacked and twisted to create a superlattice modulation potential, are currently attracting significant attention as they provide a ideal platform for both studying fundamental physics as well as promising future applications.
Imposing spatially periodic electric field via patterned dielectric material or metallic gate has also been proven to be a powerful technique to create a superlattice. It offers an excellent control of the lattice parameters and can be easily integrated into many existing device architectures, e.g. a semiconductor FET, which has an advantage of well-established fabrication technology and superb device quality.
Using this approach, we demonstrate formation of artificial Fermi surfaces by applying a weak modulation potential and measuring quantum oscillations in the magnetoresistance. Furthermore, we increase the potential modulation to create an artificial 2D bandstructure. The low field Hall resistance shows multiple transitions from electron-like to hole-like behaviour as the chemical potential is swept through the different artificial bands, consistent with our band structure calculations. We are able to continuously tune the artificial bandstructure from free electrons to those of electrons in graphene-like and eventually Kagome-like bands.
Date and Time
Location
Hosts
Registration
- Date: 25 Aug 2023
- Time: 02:00 PM to 03:00 PM
- All times are (UTC+08:00) Perth
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- The University of Western Australia
- Fairway Entrance 2
- Crawley, Western Australia
- Australia 6009
- Building: Electrical, Electronic and Computer Engineering Building
- Room Number: 303
Speakers
Oleh Klochan of University of New South Wales
Biography:
Dr. Klochan has graduated from Lviv National University in Ukraine majoring in Physics of Semiconductors and completed his PhD in Condensed Physics at UNSW in 2008. He received thr ARC DECRA Fellowship in 2013 and accepted Lecturer at the School of Science at UNSW Canberra in 2018. His expertise is in field of low temperature transport measurements of nanoscale semiconductor devices. Oleh has been working with a broad range of mesoscopic electronic devices based on GaAs material system. These include two, one and zero dimensional devices with both electrons and holes as charge carriers. Currently Oleh is a CI of an ARC CoE in Future Low- Energy Electronics Technology, working on fabrication and characterization of artificially designed electronic materials built on conventional semiconductor systems using nanopatterned lateral superlattices.
Email:
Address:G24, BLD 26, PEMS South, UNSW, Canberra, Australia