Giant Microwave Absorption in Metallic Grains: Relaxation Mechanism

TL;DR

This paper demonstrates that small metallic grains exhibit significant microwave absorption at low temperatures due to a mesoscopic relaxation mechanism, leading to giant magnetoresistance and strong temperature dependence of conductivity.

Contribution

It introduces a new relaxation mechanism explaining microwave absorption in metallic grains, with predictions of large magnetoresistance and temperature effects.

Findings

Giant positive magnetoresistance predicted

Strong temperature dependence of microwave conductivity

Microscopic relaxation mechanism identified

Abstract

We show that the low frequency microwave absorption of an ensemble of small metallic grains at low temperatures is dominated by a mesoscopic relaxation mechanism. Giant positive magnetoresistance and very strong temperature dependence of the microwave conductivity is predicted.