Contribution of Nonparabolicity to Longitudinal Magnetoresistance at Quantum Magnetic Fields

In this communication we report that in the quantum region of magnetic field ($\hslash {\omega }_c\gg k_{\mathrm{B}}T$) the nonparabolicity alone leads to a nonzero longitudinal magnetoresistance even if the energy and magnetic-field dependence of the relaxation time is ignored.