Bose-Einstein Condensation of Magnons and Spin Superfluidity in the Polar Phase of HE 3

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number025303
Pages (from-to)1-6
JournalPhysical Review Letters
Volume121
Issue number2
Publication statusPublished - 12 Jul 2018
MoE publication typeA1 Journal article-refereed

Researchers

Research units

  • Lancaster University
  • RAS
  • Moscow Institute of Physics and Technology
  • Landau Institute for Theoretical Physics

Abstract

The polar phase of He3, which is topological spin-triplet superfluid with the Dirac nodal line in the spectrum of Bogoliubov quasiparticles, has been recently stabilized in a nanoconfined geometry. We pump magnetic excitations (magnons) into the sample of polar phase and observe how they form a Bose-Einstein condensate, revealed by coherent precession of the magnetization of the sample. Spin superfluidity, which supports this coherence, is associated with the spontaneous breaking of U(1) symmetry by the phase of precession. We observe the corresponding Nambu-Goldstone boson and measure its mass emerging when applied rf field violates the U(1) symmetry explicitly. We suggest that the magnon BEC in the polar phase is a powerful probe for topological objects such as vortices and solitons and topological nodes in the fermionic spectrum.

Download statistics

No data available

ID: 27177110