The fractional quantum Hall effect is a physical phenomenon in which the Hall conductance of 2-dimensional electrons shows precisely quantized plateaus at fractional values of , where e is the electron charge and h is the Planck constant.

The quantum spin Hall state is a state of matter proposed to exist in special, two-dimensional semiconductors that have a quantized spin-Hall conductance and a vanishing charge-Hall conductance.

the "quantum" version of the anomalous Hall effect.