Quantum mechanics

Spin (aerodynamics)

Nernst equation

Ferromagnetism

Spin wave

Magnon

Berry connection and curvature

Thermodynamics

Physics

Nonlinear system

Geometric phase

Condensed matter physics

Electrode

Nernst effect

Physical Review Research

In this Letter, we study the spin Nernst effect (SNE) of magnons in the nonlinear response regime. We derive the formula for the nonlinear magnon spin Nernst current by solving the Boltzmann equation and find out that it is described by an extended Berry curvature dipole of magnons. The nonlinear magnon SNE is expected to occur in various N\'eel antiferromagnets without Dzyaloshinskii-Moriya interaction. In particular, the nonlinear spin Nernst current in the honeycomb and diamond lattice antiferromagnets can be controlled by strain/pressure.

Nonlinear magnon spin Nernst effect in antiferromagnets and strain-tunable pure spin current