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 the 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 disorder-induced polymorphism [1] and unprecedentedly high radiation tolerance of gallium oxide [2], through the discovery of quantum color centers in silicon [3-4], towards the fabrication of quantum memories in lithium niobate [5]. 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.

Students who take the "Colloquium" course must attend.