My querry is related to the paper "Persistence of chirality in the Su-Schrieffer-Heeger model in the presence of on-site disorder" (DOI : 10.1103/PhysRevB .101 .144204) .
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The Hamiltonian for the SSH model on an N - site chain is written as
H
SSH
=
N-1
∑
n=1
[1+
n
(-1)
u]{
c
n+1
c
n
+
c
n
c
n+1
}
where
c
n
(
c
n
)isthecreation(annihilation)operatorforsiten;
t
0
isthehoppingstrength;anduisthedimensionlessstrengthofthestaggerinthehopping.Ifadomainwallisintroducedinto​​theparameteruinthefollowingform:​​u=
u
0
tanh
n-
n
0
ξ/a
​​where
u
0
specifiestheamplitudeofthedomainwall,
n
0
isthecenterofthedomainwall,ξisthewidthofthedomain​​wallandaisthelatticespacing.​​Now,weintroducedisorderintheformofarandomon-site​​potentialwiththeHamiltonianas
H
dis
=
N
∑
n=1
ϵ
n
c
n
c
n
where
ϵ
n
isarandomvariabledrawnfromauniformdistributionon[−W,W].TheauthorsoftheabovementionedpaperhavediagonalizedtheHamiltonian"H=
H
SSH
+
H
dis
"foran​​N=500sitechainandaveragedover50000disorderconfigurationstoobtainthefollowingFig.2.
My querry is - (1) How can we obtain this figure?
(2) How can we get Fig .3 of the same paper?