MPS & MPO Algebra

 inner(A::DenseMPS, B::DenseMPS)

Return the inner product ⟨A, B⟩ between MPS/MPO A and B.

mul!(C::DenseMPS, A::SparseMPO, B::DenseMPS, α::Number, β::Number; kwargs...)

Compute C = α A*B + β C variationally via 2-site update, where A is a sparse MPO, B and C are dense MPS/MPO. Note 'B' cannot reference to the same MPS/MPO with C.

mul!(C::DenseMPS, A::SparseMPO, B::DenseMPS; kwargs...)

Compute C = A*B by letting α = 1 and β = 0.

Kwargs

 trunc::TruncationScheme = truncbelow(MPSDefault.tol) & truncdim(MPSDefault.D)
 GCstep::Bool = false
 GCsweep::Bool = false
 maxiter::Int64 = 8
 disk::Bool = false
 tol::Float64 = 1e-8
 verbose::Int64 = 0
 CBEAlg::CBEAlgorithm = NoCBE()
 lsnoise::AbstractVector{Float64} = Float64[]

Note CBE can only be used when α ≠ 0.

rmul!(A::DenseMPS, b::Number)

In-place multiplication A -> b*A where b is a scalar.

 axpby!(α::Number, x::DenseMPS, β::Number, y::DenseMPS; kwargs...)

Compute y = α*x + β*y variationally via 2-site update, where x and y are dense MPS/MPO. Note 'x' cannot reference to the same MPS/MPO with y.

Kwargs

 trunc::TruncationScheme = truncbelow(MPSDefault.tol) & truncdim(MPSDefault.D)
 GCstep::Bool = false
 GCsweep::Bool = false
 maxiter::Int64 = 8
 disk::Bool = false
 tol::Float64 = 1e-8
 verbose::Int64 = 0
 lsnoise::AbstractVector{Float64} = Float64[]