Conventional magnon BEC in YIG film

TL;DR

This paper reports the discovery of room-temperature magnon Bose-Einstein condensation in YIG films, demonstrating a coherent magnon state with potential for supermagnonic applications under ambient conditions.

Contribution

It presents the first observation of room-temperature magnon BEC in ferrimagnetic YIG films, showing sustained coherence and spin superfluidity signatures.

Findings

Observation of long-lived induction decay signals indicating spin superfluidity

Demonstration of persistent magnon BEC maintained by continuous RF replenishment

Potential for supermagnonic applications at room temperature

Abstract

The conventional magnon Bose-Einstein condensation (BEC of magnons with k = 0) is a coherent state of excited magnons described by a common wave function. It was observed first in antiferromagnetic superfluid states of 3He. Here we report on the discovery of a very similar magnon BEC in ferrimagnetic film at room temperature. The experiments were performed in Yttrium Iron Garnet (YIG) films at a magnetic field oriented perpendicular to the film. The high-density quasiequilibrium state of excited magnon was formed by methods of pulse and/or Continuous Waves (CW) magnetic resonance. We have observed a Long Lived Induction Decay Signals (LLIDS), well known as a signature of spin superfluidity. We demonstrate that the BEC state may maintain permanently by continuous replenishment of magnons with a small radiofrequency (RF) field. Our finding opens the way for development of potential supermagnonic applications at an ambient conditions.