This book unravels and reaffirms the potential of magneto-transport measurements for being an excellent characterization technique. The book centers on the quantum magnetotransport measurements of AlGaN/GaN HEMT structures comprising 2DEG at the interface and some other heterostructures. The interpretation of experimental response of Longitudinal Magnetoresistance (Rxx) and Transverse Magnetoresistance or Hall Resistance (Rxy) measured as a function of temperature, T (ranging between 1.8 K and 300K) and perpendicular magnetic field, B (varied from 0-8 Tesla) has been discussed comprehensively...