Hidden Moments

This chapter traces Anderson’s work from his invention of an impurity model to understand the fate of a magnetic atom immersed in a non-magnetic metal to his solution of the Kondo problem using an early version of the renormalization group invented by him and later generalized by Ken Wilson. Important events on this path are the experimental impetus provided by Bernd Matthias, the Coulomb repulsion model of insulating behavior due to Nevill Mott, and Jacques Friedel’s ideas about treating atoms embedded in metals. Speculation is offered about the award of the 1977 Nobel Prize to Anderson, Mott, and Van Vleck.

Geometry, induced magnetism and modified electronic behaviors for magnetic atom adsorption on antimonene nanotubes

The detailed first-principles calculations show that TM adsorption can imprint versatile magnetism into antimonene nanotubes. A significant carrier polarity and spin polarity of mobility as well as the magneto-electric material property are found.

Фазовые переходы в геликоидальных ферромагнетиках с концентрационными флуктуациями локальной намагниченности

A phenomenological description of phase transitions induced by fluctuations in helicoidal ferromagnets with concentration fluctuations has been developed. For this, the method of the Ginzburg-Landau functional was used and random variables that are equal to unity in the place occupied by the magnetic atom and zero otherwise are introduced. It is shown that, due to concentration effects, the local magnetization is preserved above the temperature of the magnetic transition (TS), fluctuations of the spin spiral arise, and skirmion states arise in a magnetic field. The disappearance of vortex states is associated with the suppression of local magnetization by thermodynamic fluctuations at temperature TS (> TC). Theoretical results explain the reasons for the significant expansion of the temperature range of states of the skyrmion in a non-stoichiometric manganese monosilicide with manganese deficiency.