2018/05/31 by Nobuyuki Ōkuma, Nobuyuki Okuma · 9 citations
Engineering · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Ferromagnetism #Magnetic field #Magnetic properties of thin films #Magnetization #Magneto-Optical Properties and Applications #Magnon #Phase (matter) #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin (aerodynamics) #Superfluidity #Superposition principle #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.99.094401
published in Physical review. B./Physical review. B 99(9) (American Physical Society) · 10 pages, 4 figures
openalex publication_date 2019/03/01 · arxiv created 2019/03/04 · arxiv updated 2019/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The absence of net magnetization, which forbids any stray magnetic fields, is one of the greatest advantages of antiferromagnets in device applications. In conventional antiferromagnets, however, spin current cannot be extracted without the aid of a static magnetic field. Here, we develop a theory of antiferromagnetic optospintronics to resolve this fundamental dilemma. By coupling a linearly polarized photon and nonreciprocal magnon bands, we construct a superposition state of left- and right-handed magnon states with opposite group velocities. We numerically demonstrate that by using this superposition state, an antiferromagnetic spin current can be efficiently generated without a net magnetic field including net magnetization. We also find that the breakdown of the superposition state induces the stripe superfluid phase of a two-component Bose-Einstein condensate. Our results lay the foundation for manipulating the superposition states of emergent particles in devices.