Optical gyrotropy

Optical Gyrotropy¶

It has been suggested that materials which break spatial inversion symmetry, but not time reversal symmetry, will be optically gyrotropic and display a nonlocal Hall effect.

The optical gyrotropy arises due to the existence of the gyrotropic current in response to the time derivative of the magnetic field or the curl of the electric field, which are related by the Maxwell equation, \(\partial_t \textbf{B} = -\nabla \times \textbf{E}\).

Equation for gyrotropic current¶

\(j_g(\textbf{q},w) = \sigma_g(\textbf{q},w) i \omega B(\textbf{q},w)\)

where, \(\sigma_g(\textbf{q},w)\) is the complex gyrotropic conductivity. The real and imaginary part of the quantity lead to currents, which are in and out of phase with the MF, respectively.