Suppose I have solved for some state |\psi\rangle on a lattice of size l, is there a way to somehow ‘embed’ this state in a larger lattice of size L? That is, putting this state in an ‘empty’ background of a more sites, or equivalently, extending the original state in either direction with empty sites.
Obviously a physically appropriate way would be to start the calculation on the L lattice, but with a very strong positive bias on all the sites outside of the l window, so that the solved state would be confined within the ‘smaller’ system to begin with, but I’m wondering if we could also accomplish this from a more technical direction by manipulate the indices and sites.
(for example this naive approach does not work)
psi = someprocess(l)
s = siteinds("Fermion", L; conserved_qns = true)
M = randomMPS(s, [ "Emp" for _ in 1:L])
M[ 1 : l] = psi