Switchable quantum material promises real-time control for future chips

US researchers identify a nickel sulfide compound, KxNi4S2, that reversibly switches between Dirac-cone and flat-band quantum states by electrically tuning potassium content, enabling real-time control of electron speed and flow. Demonstrated at Argonne's Center for Nanoscale Materials and Advanced Photon Source, the work could simplify device design and boost future chip and sensor performance; the study was published in Matter.