Determining the pinch-off value of a gate

Pieter Eendebak pieter.eendebak@tno.nl

We determine the pinch-off value of a 1D gate scan by means of the function analyseGateSweep.

import os
import pprint
from qtt.data import load_example_dataset
from qtt.algorithms.gatesweep import analyseGateSweep, plot_pinchoff

dataset=load_example_dataset('pinchoff_scan_barrier_gate')

Determine the pinchoff value and plot the analysis. The analyseGateSweep function will return a dictionary containing (among other things) the pinch-off point, the y-value at pinch-off, the y values for the saturation lines for the curve, both high and low and the name of the swept gate.

result=analyseGateSweep(dd=dataset)
plot_pinchoff(result, ds=dataset, fig=10)

analyseGateSweep: pinch-off point -315.000, value 0.060

pprint.pprint(result)

{'_debug': {'midpoint1': -225.0, 'midpoint2': -315.0},
 '_pinchvalueX': -275.0,
 'dataset': 'd:\\dev\\qtt_release\\qtt\\src\\qtt\\exampledata\\pinchoff_scan_barrier_gate',
 'description': 'pinchoff analysis',
 'goodgate': True,
 'highvalue': 0.19978344039999998,
 'lowvalue': -0.00018635139222000001,
 'midpoint': -315.0,
 'midvalue': 0.059804586145445995,
 'pinchoff_point': -365.0,
 'pinchoff_value': 0.181798285,
 'pinchvalue': 'use pinchoff_point instead',
 'type': 'gatesweep',
 'xlabel': 'Sweep B8 [mV]'}