magnopy.LSWT.O

property

property LSWT.O

Coefficient before the one-operator terms.

Returns:

O(M, ) numpy.ndarray

Elements are complex numbers.

Notes

Before the diagonalization, the magnon Hamiltonian has the form

\[\mathcal{H} = \dots + \sqrt{N} \sum_{\alpha} \Bigl( O_{\alpha} a_{\alpha}(\boldsymbol{0}) + \overline{O_{\alpha}} a^{\dagger}_{\alpha}(\boldsymbol{0}) \Bigr) + \dots\]

where overline denotes complex conjugation. This function computes the coefficients \(O_{\alpha}\).

Examples

>>> import magnopy
>>> spinham = magnopy.examples.cubic_ferro_nn()
>>> lswt = magnopy.LSWT(spinham=spinham, spin_directions=[[0, 0, 1]])
>>> lswt.O
array([0.+0.j])