First Observation of Quantum Oscillations in Second-Order Electrical Transport
COS/ECE Professor Mingzhong Wu and his team recently published “Quantum Oscillations of Nonlinear Electrical Transport in a Topological Dirac Semimetal” in Physical Review Letters. The paper features lead author COS Associate Research Scientist Vijaysankar Kalappattil and reports a significant experimental observation of quantum oscillations that provides a new method for studying quantum material structures. Recognized for its impact, the work was designated as an “Editor’s Suggestion” by the journal.
Quantum oscillations (QO), periodic variations in electrical resistance under strong magnetic fields, have long been a key tool for studying the Fermi surface of materials. Until now, they had only been observed in linear electrical transport. The new work shows that nonlinear transport can also exhibit quantum oscillations, revealing electronic properties beyond the reach of conventional techniques.
Using thin films of the topological Dirac semimetal α-tin, the researchers demonstrated that nonlinear-transport quantum oscillations are highly sensitive to the geometry of the Fermi surface and the orientation of electron spins. This discovery establishes a powerful new experimental tool for probing quantum materials and may accelerate the search for new quantum phases and exotic electronic states.