Kvantdefekt
Kvantdefekt is a term used in condensed matter physics to describe the deviation of the local electronic environment around an impurity atom in a solid from that of a free atom. This effect arises from the interactions between the impurity's electrons and the electrons of the surrounding host lattice. Specifically, the presence of the host's electrons can screen the nuclear charge of the impurity, leading to a change in the effective potential experienced by the impurity's valence electrons. This screening can alter the energy levels, magnetic moments, and other properties of the impurity compared to its free atomic state.
The concept of kvantdefekt is particularly relevant when studying magnetic impurities in metals. The conduction electrons