The inverse Faraday effect is the effect opposite to the Faraday effect. A static magnetization ${\displaystyle {\vec {M}}(0)}$ is induced by an external oscillating electrical field with the frequency ${\displaystyle \omega }$, which can be achieved with a high intensity laser pulse for example. The induced magnetization is proportional to the vector product of ${\displaystyle {\vec {E}}}$ and ${\displaystyle {\vec {E}}^{*}}$:
${\displaystyle {\vec {M}}(0)\propto [{\vec {E}}(\omega )\times {\vec {E}}^{*}(\omega )]}$
From this equation we see that the circularly polarized light with the frequency ${\displaystyle \omega }$ should induce a magnetization along the wave vector ${\displaystyle {\vec {k}}}$. Because ${\displaystyle {\vec {E}}}$ is in the vector product, left- and right-handed polarization waves should induce magnetization of opposite signs.