Fix examples for sum of MPO representation

Author: mtfishman

examples/vumps/vumps_heisenberg.jl

@@ -57,6 +57,10 @@ function expect_two_site(ψ::InfiniteCanonicalMPS, h::ITensor, n1n2)
   return (noprime(ϕ * h) * dag(ϕ))[]
 end
 
+function expect_two_site(ψ::InfiniteCanonicalMPS, h::MPO, n1n2)
+  return expect_two_site(ψ, prod(h), n1n2)
+end
+
 Sz = [expect(ψ, "Sz", n) for n in 1:N]
 
 bs = [(1, 2), (2, 3)]

examples/vumps/vumps_hubbard_extended.jl

@@ -75,6 +75,10 @@ function expect_two_site(ψ::InfiniteCanonicalMPS, h::ITensor, n1n2)
   return (noprime(ϕ * h) * dag(ϕ))[]
 end
 
+function expect_two_site(ψ::InfiniteCanonicalMPS, h::MPO, n1n2)
+  return expect_two_site(ψ, prod(h), n1n2)
+end
+
 function expect_two_site(ψ::MPS, h::ITensor, n1n2)
   n1, n2 = n1n2
   ψ = orthogonalize(ψ, n1)

examples/vumps/vumps_ising.jl

@@ -83,7 +83,7 @@ energy_finite_total, ψ_finite = @time dmrg(H_finite, ψ_finite, sweeps)
 
 function energy_local(ψ1, ψ2, h)
   ϕ = ψ1 * ψ2
-  return (noprime(ϕ * h) * dag(ϕ))[]
+  return (noprime(ϕ * prod(h)) * dag(ϕ))[]
 end
 
 function ITensors.expect(ψ, o)

examples/vumps/vumps_ising_extended.jl

@@ -41,7 +41,7 @@ for j in 1:outer_iters
   println("\nIncrease bond dimension")
   ψ_1 = subspace_expansion(ψ_0, H; subspace_expansion_kwargs...)
   println("Run VUMPS with new bond dimension")
-  ψ_0 = vumps(H, ψ_1; vumps_kwargs...)
+  global ψ_0 = vumps(H, ψ_1; vumps_kwargs...)
 end
 
 Sz = [expect(ψ_0, "Sz", n) for n in 1:N]

examples/vumps/vumps_ising_noncontiguous.jl

@@ -48,7 +48,7 @@ for j in 1:outer_iters
   println("\nIncrease bond dimension")
   ψ_1 = subspace_expansion(ψ_0, H; subspace_expansion_kwargs...)
   println("Run VUMPS with new bond dimension")
-  ψ_0 = vumps(H, ψ_1; vumps_kwargs...)
+  global ψ_0 = vumps(H, ψ_1; vumps_kwargs...)
 end
 
 Sz = [expect(ψ_0, "Sz", n) for n in 1:N]

examples/vumps/vumps_localham_qns.jl

@@ -56,7 +56,7 @@ randn!.(ψ)
 
 function energy(ψ1, ψ2, h)
   ϕ = ψ1 * ψ2
-  return (noprime(ϕ * h) * dag(ϕ))[]
+  return (noprime(ϕ * prod(h)) * dag(ϕ))[]
 end
 
 function expect(ψ, o)