At very low temperatures and in strong magnetic fields, a two-dimensional system of electrons in a semi-conductor exhibits a conductivity which is quantized in terms of the square of the electronic charge.
At very low temperatures and in strong magnetic fields, a two-dimensional system of electrons in a semi-conductor exhibits a conductivity which is quantized in terms of the square of the electronic charge. One application of this phenomenon is obtaining a very accurate measure of the fine structure constant. FTP, name this discovery of the last 20 years which earned Klaus von Klitzing the 1985 Nobel Prize in physics.
At very low temperatures and in strong magnetic fields, a two-dimensional system of electrons in a semi-conductor exhibits a conductivity which is quantized in terms of the square of the electronic charge.
quantum Hall effect (do not accept or prompt on Hall effect)