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Abstract:
We propose an experimental setup using 3D Dirac semimetals to access a
novel phenomenon induced by the chiral anomaly. We show that the
combination of a magnetic field and a circularly polarized laser induces
a finite charge density with an accompanying axial current. This is
because the circularly polarized laser breaks time-reversal symmetry and
the Dirac point splits into two Weyl points, which results in an
axial-vector field. We elucidate the appearance of the axial-vector
field with the help of the Floquet theory by deriving an effective
Hamiltonian for high-frequency electric fields. This anomalous charge
density, i.e., the chiral pumping effect, is a phenomenon reminiscent of
the chiral magnetic effect with a chiral chemical potential. We
explicitly compute the pumped density and the axial-current expectation
value. We also take account of coupling to the chiral magnetic effect to
calculate a balanced distribution of charge and chirality in a material
that behaves as a chiral battery.
