1. Topological Magnon Bands in AFM limit of Shastry-Sutherland Lattice
Dhiman Bhowmick
Supervisor: Pinaki Sengupta

2. Model Description
Square Lattice
Shastry-Sutherland Lattice
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3. Model Description
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4. Classical Ground State
Longitudinal AFM
Spins are antiparallel along the axial sites
J=1.0, J’=1.1
Flux State
Spins rotate clockwise or anticlockwise in a plaquette
3Q-order
In plane spin-components along diagonal
Spins are tilted out of plan
Non-zero in plane DM-interaction
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5. Quantum Excitation Holstein Primakoff Transformation Spin Hamiltonian,
Magnon
Holstein Primakoff Transformation
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Spin Hamiltonian,
Magnon Hamiltonian,

6. Magnon Band and Topology
Topological Magnon Band
Topology is determined by Chern Number of the bands
, where is the eigen- vector of n-th band at k-point
C4=+1
C3=-1
C2=-1
C1=+1
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7. Experimental Realization
Magnon Thermal Hall Effect
Rare earth-tetra borides are a promising class of materials to study topological magnons. DM-interactions necessary to induce topology can be introduced by changing the symmetry of the lattice by distorting it.
Induced Temperature Gradient
Magnon Current
Temperature Gradient
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8. Thank You
Poster: 59
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