Spin Spiral Surfaces in Heisenberg Magnets: Explicit constructions of models with ground state degeneracy

Rövid cím: 
Spin Spiral Surfaces in Heisenberg Magnets
2019. 10. 25. 10:15
Building F, stairway III., seminar room of the Dept. of Theoretical Physics
Péter Balla (Wigner)

Frustration in classical spin models can lead to degenerate ground states without long-range order. In reciprocal space, these degeneracies appear as manifolds of wave vectors, their dimensionality increasing with the degree of frustration and the robustness of the disordered spin-liquid state. Here, we present a recipe to explicitly construct Heisenberg models on Bravais lattices with codimension-one manifolds, i.e., lines in two dimensions and surfaces with different Euler characteristics in three dimensions. Furthermore, we discuss the role of thermal and quantum fluctuations in stabilizing ordered states.


Based on: P Balla, Y Iqbal, K Penc, Phys. Rev. B 100, 140402(R) (2019)