171 research outputs found
Charge pumping induced by magnetic texture dynamics in Weyl semimetals
Spin-momentum locking in Weyl semimetals correlates the orbital motion of
electrons with background magnetic textures. We show here that the dynamics of
a magnetic texture in a magnetic Weyl semimetal induces a pumped electric
current that is free from Joule heating. This pumped current can be regarded as
a Hall current induced by axial electromagnetic fields equivalent to the
magnetic texture. Taking a magnetic domain wall as a test case, we demonstrate
that a moving domain wall generates a pumping current corresponding to the
localized charge.Comment: 5 pages, 1 figure, 1 tabl
SU(3) and SU(4) singlet quantum Hall states at
We report on an exact diagonalization study of fractional quantum Hall states
at filling factor in a system with a four-fold degenerate =0
Landau level and SU(4) symmetric Coulomb interactions. Our investigation
reveals previously unidentified SU(3) and SU(4) singlet ground states which
appear at flux quantum shift 2 when a spherical geometry is employed, and lie
outside the established composite-fermion or multicomponent Halperin state
patterns. We evaluate the two-particle correlation functions of these states,
and discuss quantum phase transitions in graphene between singlet states with
different number of components as magnetic field strength is increased.Comment: 5+2 pages, 3 figure
Localized charge in various configurations of magnetic domain wall in Weyl semimetal
We numerically investigate the electronic properties of magnetic domain walls
formed in a Weyl semimetal. Electric charge distribution is computed from the
electron wave functions, by numerically diagonalizing the Hamiltonian under
several types of domain walls. We find a certain amount of electric charge
localized around the domain wall, depending on the texture of the domain wall.
This localized charge stems from the degeneracy of Landau states under the
axial magnetic field, which corresponds to the curl in the magnetic texture.
The localized charge enables one to drive the domain wall motion by applying an
external electric field without injecting an electric current, which is
distinct from the ordinary spin-transfer torque and is free from Joule heating.Comment: 10 pages, 8 figure
- …