SEMINAR 2025
Novel radiation phenomena in solids:
from collective disorder-induced ordering to engineering of artificial atoms
Speaker | Andrej Kuznetsov, University of Oslo, Oslo, Norway |
Date/Time | Wednesday, 26 Feb, 3pm |
Location | S11-02-07 |
Moderator | A/Prof Jeroen Anton van Kan |
Abstract
On many occasions, structural defects bare a negative connotation, provoking efforts to reduce their contents. On the other hand, many unique properties may be engineered only by using defects in materials. Whether one considers this odyssey started with a discovery of steel by alloying iron and carbon some thousands year ago somewhere in Asia or a discovery of a p/n-junction made by a controllable electronic doping of silicon at the Bell Lab in the middle of last century – is a matter of interpreting the history. Importantly, at present, using energetic ion beams for doping or just for displacing atoms in the lattice is probably most accurate way to introduce and functionalize defects in solids. In this context, in this talk, I will review several novel observations of such radiation phenomena, starting from the collective disorder-induced ordering in gallium oxide [1-5], through the discovery of quantum color centers in silicon [6-7], towards the fabrication of quantum memories in lithium niobate [8]. With these arguments, I conclude that radiation phenomena in solids remains an important branch of modern physics, capable to contribute towards resolving the 21st century technological challenges.
[1] Azarov et al., Physical Review Letters 128, 15704 (2022)
[2] Azarov et al., Nature Communications, 14, 4855 (2023)
[3] Huang et al., Physical Review Letters 133, 226101 (2024)
[4] Azarov et al., Nano Letters (2025)
https://doi.org/10.1021/acs.nanolett.4c05727
[5] Zhao et al., Physical Review Letters, in-review and arXiv:2401.07675v3
[6] Durand et al., Physical Review Letters 126, 083602 (2021)
[7] Redjem et al., Nature Electronics 3, 738(2020)
[8] Slusar et al., Advanced Optical Materials, 2401374 (2024)

Illustration of the abrupt polymorph interfaces self-assembling via disorder included ordering at different temperatures in gallium oxide. Specifically, for the sample irradiated at 350 °C, multiple interfaces, labeled as I1-I3, comprise a polymorph heterostructure (after Ref.4).

Biography
Andrej Kuznetsov was awarded with a Ph.D. degree in physics from the Russian Academy of Sciences in 1992 and accomplished his habilitation in solid state electronics in 2000 at the Royal Institute of Technology in Sweden. In 2001 he joined the University of Oslo in Norway as an associate professor at the Department of Physics, where he was subsequently promoted to a full professor rank in 2003. From 2018 he acts as the Chair of the Centre of Excellence: Light and Electricity from Novel Semiconductors (LENS) – as a part of the Centre for Materials Science and Nanotechnology at the University of Oslo. The focus is to understand novel semiconductors, searching for new fundamental phenomena and enabling new device functionalities.