Reference

class green_ysr.lattice(**kwargs)

The atomic lattice to simulate.

kwargs:

type : string

type of lattice, 'single atom', '1D' or '2D'

N : int

Number of atoms in the system

coords : list

in the case of a '2D' lattice, a list of the atomic coordinates must be provided

pitch_x : float

for a equi-spaced '1D' chain the pitch_x is the spacing of the atoms in the chain, needed to generate the coordinates

direction : tuple

direction of elongation of the chain in cristallographic notation, e.g. (1,0) is horizontal, (1,1) is 45 degrees

alpha : float

Adimensional exchange coupling parameter

theta : float

angle describing the orientation in rad of the classical spins

U : float

adimensional potential scattering parameter

spiral : float

if inserted is the pace of the spin spiral along the chain in radiants

m : float

effective mass multiplied by pi in atomic unit

pf : float

fermi momentum in atomic units

delta : float

superconducting order parameter in atomic units

gamma : float

dynes parameter in atomic units

mode : int

fermi surface dimensionality, 1 for circular, 2 for squared

E_px : int

point of energy to calculate

E_range : tuple

extremes of the energy, set 0,2 for calculate half of the spectrum

V_range : tuple

extremes of the voltage, used when doing the convolution

spin_texture : list

list of the spin orientation of the atoms in the structure, if not provided will be ferromagnetic

Attributes:

E : array

energy array

V : array

voltage array, for convolution. The V range has to be always lower than E for the convolution.

sim : class

is the solver of the green function

par : dict

save all parameters

coord_gen()

for generating chain coordinates fiven the pitch
return array of coordinates

show_lattice()

show the lattice coordinates in a plot

map_coord_gen()

generate the coordinate for a didv map

Parameters :

spac : float

spacing in atomic units of the lattice

resolution : int

number of pixel in one line of the didv map

size : int

size of one side of the didv map in units of spac (spacing)

show_lattice_map()

show the lattice and the didv map coordinates in a plot

didv()

calculate the didv in one point
Parameters :
coord : tuple
coordinates of the measurement point
return array with spectra (normalized to normal conductance)

didv_map_calc()

caculates the didv map and store it in self.didv_map

didv_conv()

calculate the convolution with the superconducting tip at the temperature specified in self.T
Parameters :
coord : tuple
coordinates of the measurement point

Delta_t : float

pairing amplitude in the tip electrode in meV

Gamma_t : float

dynes parameter in meV
return array with tip convoluted spectra (normalized to normal conductance)

linescan()

compute a line of spectra (saved in self.LS) along the 1D chain direction, including initial and final portion of superconductor (pitch_x)
Parameters :
density : int
number of points per atom in the linescan

LSconvolute()

compute the convoluted linescan (saved in self.LSC) at the temperature specified in self.T
Parameters :
coord : tuple
coordinates of the measurement point

Delta_t : float

pairing amplitude of the tip electrode in meV

Gamma_t : float

Dynes parameter of the tip

explorer()

opens a slider plot to explore self.didv_map in constant energy cuts

update_energy()

vital to explorer()

update_cscale()

vital to explorer()

class green_ysr.green(**kwargs)

To calculate the green function.

Parameters :

N : int

Number of atoms in the system

alpha : float

Adimensional exchange coupling parameter

theta : float

angle describing the orientation in rad of the classical spins

r__ : list

set of atomic coordinates

U : float

adimensional potential scattering parameter

m : float

effective mass multiplied by pi in atomic unit

pf : float

fermi momentum in atomic units

delta : float

superconducting order parameter in atomic units

gamma : float

dynes parameter in atomic units

mode : int

fermi surface dimensionality, 1 for circular, 2 for squared

Attributes:

s0-1-3 : numpy array

pauli matrices

G0()

analitical form of the unperturbed green function

V()

Potential matrix of each impurity return a 4x4 matrix

G0_()

green function of the Dyson series return a 4x4N matrix

G()

full green function return a 4Nx4N matrix

DOS()

compute the spectrum of the green function

ElecDOS()

Compute the electron part of the spectral function

ElecDOS()

Compute the hole part of the spectral function

Additional functions

fdd()

Fermi dirac distribution

dynesdos()

Dynes dos of a superconductor

dynesConvolute()

numerical convolution of a conducance array

save_obj()

save an arbitrary object

load_obj()

load an arbitrary object given its path without extension

sim_save()

to save a simulation, including important parameters in the name

plot_LS()

to show the result of a line of spectra calculated with lattice()

set_size_cm()

to change the size of a figure axis