Inductance and capacitance emerged from topological electromagnetism

We theoretically propose novel functionalities of inductance and capacitance in heterostructures of topological insulators and magnets. Topological insulators show anomalous responses between electricity and magnetism, which are described not by the conventional Maxwell’s equations, but by topological quantum field theory. Based on topological quantum field theory, we establish a unified theoretical framework applicable in arbitrary dimensions, to extract inductance and capacitance in topological insulators. We demonstrate the emergence of inductance and capacitance in several magnetic heterostructure setups, and show their advantages in achieving high operation frequency and high power efficiency.