Hi,

I am trying to evaluate entanglement entropy for 1D system with OBC by keeping fix J and variable t2. There is a phase transition from 2-Majorana phase to 4-Majorana phase. For J=0, entanglement entropy is non-vanishing and there is a peak in entanglement entropy at phase transition but as soon as I turn on J, entanglement entropy turns out to be zero (near 10^(-7)). I used DMRG (ITensor Julia) to calculate ground state wavefunction and it seems like it is choosing a state with least entanglement for non-zero J interaction. Is there any way to force dmrg in ITensor Julia to get correct entangled ground state? I would really appreciate any help or suggestions.

Thank you so much!

I am using following Hamiltonian:

sites = siteinds("S=1/2",N1)

for j=1:N1-1

ampo += -1/2,"Sx",j,"Sx",j+1

ampo += J/4,"Sz",j,"Sz",j+1

end

for j=1:N1-2

ampo += t2,"Sx",j,"Sz",j+1,"Sx",j+2

end