Note on Angular Momentum of Phonons in Chiral Crystals

Phonon angular momentum in chiral materials has been widely studied in spintronics and condensed matter physics. In chiral crystals, this is not the conserved quantity in contrast to the pseudo-angular momentum. To highlight this point and to understand the behavior of the angular momentum, we reexamined phonon dispersion theory based on the irreducible representation of helix and found the distinction of these angular momentum is originated from chirality.Comment: 2 pages, 2 figure

Interplay of randomness, electron correlation, and dimensionality effects in quasi-one-dimensional conductors

We study the interplay of randomness, electron correlation, and dimensionality effects in weakly coupled half-filled Hubbard chains with weak quenched random potentials, based on the renormalization-group (RG) approach. We perform a two-loop RG analysis of an effective action derived by using the replica trick, and examine the following crossovers and phase transitions from an incoherent metal regime: (1) a crossover to the Anderson localization regime, (2) an antiferromagnetic phase transition, and (3) a crossover to the quasi-one-dimensional weak-localization regime. The case of d=1+ε (ε≪1) dimensions is also mentioned

Theory of spin resonance in a chiral helimagnet

It is suggested that marked features of symmetry-breaking mechanism and elementary excitations in chiral helimagnet come up as visible effects in electron-spin-resonance ESR profile. Under the magnetic field applied parallel and perpendicular to the helical axis, elementary excitations are, respectively, described by the helimagnon associated with rotational symmetry breaking and the magnetic kink crystal phonon associated with translational symmetry breaking. We demonstrate how the ESR spectra distinguish these excitations