Giant odd-parity magnetoresistance in a non-magnetic two-dimensional electron gas

Odd-parity magnetoresistance (OMR), characterized by its asymmetric response to magnetic field reversal, has remained limited in practical use due to its typically small magnitude and limited control in conventional magnetic metals. Here, we report a gate-tunable OMR effect in high-mobility AlGaN/GaN two-dimensional electron gas (2DEG) heterostructures, exhibiting a giant OMR coefficient exceeding 60%. Dual-gate control enables independent tuning of carrier density, achieving a highly linear and reversible OMR response, which is further enhanced by device geometry optimization. The effect arises from spatially engineered gradients of the Hall coefficient and magnetic-field-induced symmetry breaking. These results establish AlGaN/GaN 2DEGs as a robust and tunable platform for high-performance OMR devices, with potential applications in nonreciprocal electronics and magnetic sensing.