Conversion between electron spin and microscopic atomic rotation
Abstract
We theoretically investigate the microscopic mechanism of conversion between the electron spin and the microscopic local rotation of atoms in crystals. In phonon modes with angular momenta, the atoms microscopically rotate around their equilibrium positions in crystals. In a simple toy model with phonons, we calculate the spin expectation value by using the adiabatic series expansion. We show that the timeaveraged spin magnetization is generated by the microscopic local rotation of atoms via the spinorbit interaction. On the other hand, in the system with a simple vibration of atoms, timeaveraged spin magnetization becomes zero due to the timereversal symmetry. Moreover, the magnitude of the timeaveraged spin magnetization depends on the inverse of the difference of instantaneous eigenenergy, and we show that it becomes smaller in band insulators with a larger gap.
 Publication:

Physical Review Research
 Pub Date:
 June 2020
 DOI:
 10.1103/PhysRevResearch.2.023275
 arXiv:
 arXiv:2006.00015
 Bibcode:
 2020PhRvR...2b3275H
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Other Condensed Matter
 EPrint:
 11 pages, 7 figures, to be published in Phys. Rev. Research