Dynamical Multiferroicity

A static spin-spiral in space can, via the Dzyaloshiksii-Moriya interaction lead to an effective polarisation; by exploiting the duality between electricity and magnetism in Maxwell’s equations, a complementary effect – Dynamical Multiferroicity – is possible.

In dynamical multiferroicity, a magenetic moment results from electric dipoles with transverse (rotational) motion:

    \[ \mathbf{m} = \lambda \mathbf{p}\times \partial_t \mathbf{p} \]

In a paraelectric material where the polarisation is zero, induced magnetic signatures of dynamical multiferroicity may be present due to fluctuating electric dipoles. One type of material where this might occur is in quantum paraelectrics where quantum fluctuations prevent the appearance of ferroelectric order.

Seminal paper:
“Dynamical Multiferroicity”
Dominik Maximilian Juraschek, Michael Fechner, Alexander V. Balatsky, Nicola Ann Spaldin
Phys. Rev. Materials 1, 014401 (2017)

Other key papers:
Dynamic multiferroicity of a ferroelectric quantum critical point
K. Dunnett, J.-X. Zhu, N. A. Spaldin, V. Juricic, A. V. Balatsky