Nonreciprocal superposition state in antiferromagnetic optospintronics

Abstract

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 opto-spintronics 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.

10 pages, 4 figures

References in corpus (12)

• Dissipationless Quantum Spin Current at Room Temperature
• Observation of the Magnon Hall Effect
• Spin pumping and spin-transfer torques in antiferromagnets
• Topological Magnon Insulator in Insulating Ferromagnet
• Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light
• Dirac magnons in honeycomb ferromagnets
• Spin Seebeck effect in antiferromagnets and compensated ferrimagnets
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• Spin Seebeck effect in a polar antiferromagnet $\alpha$-Cu${}_2$V${}_2$O${}_7$
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• Magnonic triply-degenerate nodal points

Cited by in corpus (4)

• Nonreciprocal Magnon by Symmetric Anisotropic Exchange Interaction in Honeycomb Antiferromagnet
• Essential model parameters for nonreciprocal magnons in multisublattice systems
• Nonreciprocal magnon excitations by the Dzyaloshinskii-Moriya interaction on the basis of bond magnetic toroidal multipoles
• Ferroelectricity in a magnon Bose-Einstein condensate: Nonreciprocal superfluidity, exceptional points, and Majorana bosons