def Simmons(V, params):
"""Simmons model tunnelling
V=bias voltage, params=[A, phi, d]
A in m^2, phi barrier height in eV, d barrier width in angstrom
Simmons model as in
Simmons J. App. Phys. 34 6 1963
"""
return _SF.Simmons(V, *params)
d.curve_fit(SF.simmons, p0=[2500, 5.2, 15.0], result=True, header="curve_fit")
d.setas = "xyey"
d.plot(fmt=["r.", "b-"])
d.annotate_fit(
SF.simmons,
x=0.25,
y=0.25,
prefix="simmons",
fontdict={
"size": "x-small",
"color": "blue"
},
)
d.setas = "xye"
fit = SF.Simmons()
p0 = [2500, 5.2, 15.0]
d.lmfit(SF.Simmons, p0=p0, result=True, header="lmfit")
d.setas = "x...y"
d.plot(fmt="g-")
d.annotate_fit(
fit,
x=0.65,
y=0.25,
prefix="Simmons",
fontdict={
"size": "x-small",
"color": "green"
},
)