Quantum Oscillations of Nonlinear Electrical Transport in a Topological Dirac Semimetal

Quantum oscillations in electrical transport have long served as a powerful probe of fundamental Fermi surface physics. To date, however, such studies have been restricted to linear electrical transport. This letter presents the experimental observation of quantum oscillations in nonlinear electrical transport and, more importantly, demonstrates their ability to uncover key features of the Fermi surface that lie beyond the reach of linear-transport quantum-oscillation techniques. Using α-Sn, a topological Dirac semimetal known to support both linear and nonlinear transport, this study shows that quantum oscillations of nonlinear resistance are highly sensitive to both the geometry and spin texture of the Fermi contour-features to which linear counterparts are insensitive. Further, nonlinear-transport oscillations exhibit markedly distinct dependencies on magnetic field and temperature compared to their linear analogs. These findings establish nonlinear-transport quantum oscillations as a transformative tool for exploring Fermi surface physics, opening new avenues for revealing hidden Fermi surface properties in known materials and discovering new exotic electronic states and phases.