Inductance Due to Spin Current

TL;DR

This paper explores the inductance associated with spin currents in spintronic devices, revealing that spin currents induce electric fields leading to inductance, which is typically very small due to relativistic effects, offering advantages for low-inductance applications.

Contribution

It introduces the concept of inductance in spin currents, clarifies the relation between electromotive force and flux, and highlights the relativistic origin of the small inductance in spintronic systems.

Findings

Spin currents induce electric fields and thus exhibit inductance.

Relativistic effects make the inductance extremely small.

The analysis applies similarly to electric dipole currents and polarized bound charges.

Abstract

The inductance of spintronic devices that transport charge neutral spin currents is discussed. It is known that in a media that contains charge neutral spins, a time-varying electric field induces a spin current. We show that since the spin current itself produces an electric field, this implies existence of inductance and electromotive force when the spin current changes with time. The relations between the electromotive force and the corresponding flux, which is a vector calculated by the cross product of electric field and the trajectory of the device, are clarified. The relativistic origin generally renders an extremely small inductance, which indicates the advantage of spin current in building low inductance devices. The same argument also explains the inductance due to electric dipole current, and applies to physical dipoles consist of polarized bound charges.