TCA file formats

Tunnel current amplitude (TCA) tables are created by the cd and cm commands. They consist of real and imaginary parts of the pair and quasiparticle amplitudes, on a scale of normalized potential across the structure, where the unit value is the sum of the gap energies of the two electrodes. The scale extends from 0 to 2 in these units.

There actually are three formats available, selectable with options to the cd and cm commands.

option: -rd
The file name is described in the previous section, with a suffix ``.data''. This is a generic numerical format, consisting of a comment line and six columns of numbers. The number of data lines is the value given with the ``-x'' option to the cd command, defaulting to 500. The example below illustrates the format.

#    X            Jpair_real   Jpair_imag   Jqp_real     Jqp_imag
0    1.00000e-03  7.50623e-01  2.85275e-04  -7.50625e-01 3.37356e-04
1    5.00601e-03  7.51136e-01  1.36358e-03  -7.51123e-01 1.62410e-03
2    9.01202e-03  7.51643e-01  2.27465e-03  -7.51594e-01 2.74301e-03
3    1.30180e-02  7.52144e-01  3.03372e-03  -7.52040e-01 3.70900e-03
...
498  1.99599e+00  4.22402e-01  -5.29166e-01 1.52235e-02  1.87539e+00
499  2.00000e+00  4.21420e-01  -5.28564e-01 1.51180e-02  1.87962e+00

The other two options emit the data using the SPICE ``rawfile'' format. This is a format developed for plot data in Berkeley Spice3, which is supported by most plotting programs, including Synopsys WaveView and the load function of WRspice. The only difference is that one format ouptuts complex numbers for two variables (pair and quasiparticle amplitudes), while the other format outputs real values for four variables (the real and imaginary parts of the amplitudes).

option: -r
The file name is described in the previous section, with a suffix ``.raw''. Output is in rawfile format using complex numbers.

option: -rr
The file name is described in the previous section, with a suffix ``.raw''. Output is in rawfile format using real numbers.

The rawfile format description can be found in A.1.