Band map

The band map class and allowed operations on it.

class xarpes.band_map.band_map(intensities, angles, ekin, energy_resolution=None, temperature=None, hnuminphi=None, hnuminphi_std=None)

Class for the band map from the ARPES experiment.

Parameters:

intensitiesndarray

2D array of counts for given (E,k) or (E,angle) pairs [counts]

anglesndarray

1D array of angular values for the abscissa [degrees]

ekinndarray

1D array of kinetic energy values for the ordinate [eV]

energy_resolutionfloat

Energy resolution of the detector [eV]

temperaturefloat, None

Temperature of the sample [K]

hnuminphifloat, None

Kinetic energy minus the work function [eV]

hnuminphi_stdfloat, None

Standard deviation of kinetic energy minus work function [eV]

property hnuminphi

Returns the photon energy minus the work function in eV if it has been set, either during instantiation, with the setter, or by fitting the Fermi-Dirac distribution to the integrated weight.

Returns:

hnuminphifloat, None

Kinetic energy minus the work function [eV]

property hnuminphi_std

Returns standard deviation of the photon energy minus the work function in eV.

Returns:

hnuminphi_stdfloat

Standard deviation of energy minus the work function [eV]

shift_angles(shift)

Shifts the angles by the specified amount in degrees. Used to shift from the detector angle to the material angle.

Parameters:

shiftfloat

Angular shift [degrees]

fit_fermi_edge(hnuminphi_guess, background_guess=0.0, integrated_weight_guess=1.0, angle_min=-inf, angle_max=inf, ekin_min=-inf, ekin_max=inf, ax=None, **kwargs)

Fits the Fermi edge of the band map and plots the result. Also sets hnuminphi, the kinetic energy minus the work function in eV. The fitting includes an energy convolution with an abscissa range expanded by 5 times the energy resolution standard deviation.

Parameters:

hnuminphi_guessfloat

Initial guess for kinetic energy minus the work function [eV]

background_guessfloat

Initial guess for background intensity [counts]

integrated_weight_guessfloat

Initial guess for integrated spectral intensity [counts]

angle_minfloat

Minimum angle of integration interval [degrees]

angle_maxfloat

Maximum angle of integration interval [degrees]

ekin_minfloat

Minimum kinetic energy of integration interval [eV]

ekin_maxfloat

Maximum kinetic energy of integration interval [eV]

axMatplotlib-Axes / NoneType

Axis for plotting the Fermi edge on. Created if not provided by the user.

Returns:

figMatplotlib-Figure

Figure containing the Fermi edge fit

Other Parameters:

**kwargsdict, optional

Additional arguments passed on to add_fig_kwargs. See the keyword table below.

Notes

Keyword arguments controlling the display of the figure:

kwargs	Meaning
title	Title of the plot (Default: None).
show	True to show the figure (default: True).
savefig	“abc.png” or “abc.eps” to save the figure to a file.
size_kwargs	Dictionary with options passed to fig.set_size_inches e.g. size_kwargs=dict(w=3, h=4)
tight_layout	True to call fig.tight_layout (default: False)
ax_grid	True (False) to add (remove) grid from all axes in fig. Default: None i.e. fig is left unchanged.
ax_annotate	Add labels to subplots e.g. (a), (b). Default: False
fig_close	Close figure. Default: False.