magnopy.examples.ivuzjo

magnopy.examples.ivuzjo(N=10, J=10)

Prepare a Hamiltonian as in the example of [1].

\[\mathcal{H} = -\dfrac{1}{2} \sum_{\mu, \nu} J \boldsymbol{S}_{\mu} \cdot \boldsymbol{S}_{\mu+\nu} - \dfrac{1}{2} \sum_{\mu, \nu} \dfrac{J}{2} \boldsymbol{r}_{\nu} \left( \boldsymbol{S}_{\mu} \times \boldsymbol{S}_{\mu+\nu} \right) + \sum_{\mu} J \boldsymbol{\hat{z}} \boldsymbol{S}_{\mu}\]

Parameters:

Nint, default 10

Size of the supercell (N x N).

Jfloat, default 10

Value of the isotropic exchange in energy units (meV).

Returns:

spinhamSpinHamiltonian

Spin Hamiltonian (with magnetic field)

References

[1]

Ivanov, A.V., Uzdin, V.M. and Jónsson, H., 2021. Fast and robust algorithm for energy minimization of spin systems applied in an analysis of high temperature spin configurations in terms of skyrmion density. Computer Physics Communications, 260, p.107749.

Examples

To create an example Hamiltonian use

>>> import magnopy
>>> spinham = magnopy.examples.ivuzjo()