triqs_dft_tools.sumk_dft_transport.transport_function

triqs_dft_tools.sumk_dft_transport.transport_function(beta, directions, hopping, velocities, energy_window, n_om, rot_symmetries)

Calculates the transport function

\[\Phi_\alpha\beta(\omega) = \sum_k v_{k,\alpha} v_{k,\beta} \delta(\omega-\varepsilon)\]

in the direction \(\alpha\beta\).

Parameters:

betadouble

Inverse temperature \(\beta\).

directionslist of string, optional

\(\alpha\beta\) e.g.: [‘xx’,’yy’,’zz’,’xy’,’xz’,’yz’].

hoppingdouble array

Hamiltonian in band basis \(\epsilon(k)\)

veolcitiescomplex array

matrix elements derivative of Hamiltonian \(\frac{d\epsilon(k)}{dk}\)

energy_windowlist of double

Specifies the upper and lower limit of the frequency integration for \(\Omega=0.0\). The window is automatically enlarged by the largest \(\Omega\) value, hence the integration is performed in the interval [energy_window[0]-max(Om_mesh), energy_window[1]+max(Om_mesh)].

n_ominteger

Number of equidistant frequency points in the interval [energy_window[0]-max(Om_mesh), energy_window[1]+max(Om_mesh)]. This parameters is only used if with_Sigma = False.

rot_symmetrieslist of 3 x 3 matrices

rotational symmetries to restore the full FBZ

Returns:

transp_funcdictionary of double array

transport function in each direction, frequencies given by energy_window