Emergence of inductance and capacitance from topological electromagnetism

TL;DR

This paper demonstrates that topological electromagnetism in insulators can generate inductance and capacitance, offering power-efficient alternatives to classical components through a theoretical framework and heterostructure demonstrations.

Contribution

It introduces a generic topological field theory framework to derive emergent inductance and capacitance in insulators, extending the concept beyond metallic systems.

Findings

Emergent inductance and capacitance are demonstrated in heterostructures.

Insulators suppress power loss due to lack of Joule heating.

High Q-factor and low current operation enable power-efficient devices.

Abstract

Topological electromagnetism owing to nontrivial momentum-space topology of electrons in insulators gives rise to diverse anomalous magnetoelectric responses. While conventional inductors and capacitors are based on classical electromagnetism described by Maxwell's equations, here we show that topological electromagnetism in combination with spin dynamics in magnets also generates an inductance or a capacitance. We build a generic framework to extract the complex impedance on the basis of topological field theory, and demonstrate the emergence of an inductance or a capacitance in several heterostructure setups. In comparison with the previously-studied emergent inductances in metallic magnets, insulators highly suppress the power loss, because of the absence of Joule heating. We show that the inductance from topological electromagnetism is achieved at low current and high frequency, and is also advantageous in its power efficiency, as characterized by the high quality factor (Q-factor).