Nernst Effect: How a Temperature Difference Generates an Electric Field

The Nernst Effect describes the occurrence of an electric field \( \class{purple}{\boldsymbol{E}_{\text y}} \) perpendicular to a temperature gradient in a material situated in a magnetic field \( \class{violet}{B_{\text z}} \). Since this effect is practically similar to the Hall Effect, with the only distinction being that, instead of the electric field, a temperature gradient is the cause of electron motion, this effect is also called the thermal Hall effect.

Due to the temperature difference \( \frac{\text{d} T}{\text{d} x} \) in the material, which is located in a magnetic field \(B_{\text z}\), the electrons move towards the hot side of the conductor. Since this movement takes place in a magnetic field, the electrons are deflected by the Lorentz force, so that in this case an electric field \( E_{\text y} \) forms in the \(y\) direction.