gftool.lattice.rectangular.hilbert_transform

gftool.lattice.rectangular.hilbert_transform(xi, half_bandwidth, scale)[source]

Hilbert transform of non-interacting DOS of the rectangular lattice.

The Hilbert transform is defined

\[\tilde{D}(ξ) = ∫_{-∞}^{∞}dϵ \frac{DOS(ϵ)}{ξ − ϵ}\]

The lattice Hilbert transform is the same as the non-interacting Green’s function.

Parameters:
xicomplex np.ndarray or complex

Point at which the Hilbert transform is evaluated.

half_bandwidthfloat

Half-bandwidth of the DOS of the 2D rectangular lattice. The half_bandwidth corresponds to the nearest neighbor hopping \(t=D/2/(scale+1)\).

scalefloat

Relative scale of the different hoppings \(t_1=scale*t_2\). scale=1 corresponds to the square lattice.

Returns:
complex np.ndarray or complex

Hilbert transform at xi.

Notes

Relation between nearest neighbor hopping t, scale γ and half-bandwidth D

\[2(γ+1)t = D\]