errors in correlator function for custom itensor operator

ITensor Julia Questions
1

Hi everyone
I am trying to simulate a correlation function of multiple sites. The custom itensor operators I defined are:

d=3;
function ITensors.op(::OpName"exp2N", ::SiteType"Qudit", d::Int; m=1) 
  M = zeros(d,d)
  M[m,m] = exp(2*pi*2*im/L)
  return M
end
function ITensors.op(::OpName"exp3N", ::SiteType"Qudit", d::Int; m=1)
  M = zeros(d,d)
  M[m,m] = exp(2*pi*3*im/L)
  return M
end
function ITensors.op(::OpName"exp4N", ::SiteType"Qudit", d::Int; m=1)
  M = zeros(d,d)
  M[m,m] = exp(2*pi*4*im/L)
  return M
end

then I want to calculate the correlation function

c = correlator(psio, ("exp2N", "exp3N","exp4N"), [(1, 2, 3)])

But I get a following error:

ERROR: InexactError: Float64(0.30901699437494745 + 0.9510565162951535im)
Stacktrace:

Real at .\complex.jl

convert(#unused#::Type{Float64}, x::ComplexF64) at .\number.jl

setindex! at .\array.jl

op(::OpName{:exp2N}, ::SiteType{Qudit}, d::Int64; m::Int64) at c:\Users\lenovo\Desktop\code\test.jl

op at c:\Users\lenovo\Desktop\code\test.jl

#op#1163 at C:\Users\lenovo.julia\packages\ITensors\xUMVS\src\physics\site_types\qudit.jl

op(::OpName{:exp2N}, ::SiteType{Qudit}, ::Index{Int64}) at C:\Users\lenovo.julia\packages\ITensors\xUMVS\src\physics\site_types\qudit.jl

op(name::String, s::Index{Int64}; adjoint::Bool, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}) at C:\Users\lenovo.julia\packages\ITensors\xUMVS\src\physics\sitetype.jl

op(name::String, s::Index{Int64}) at C:\Users\lenovo.julia\packages\ITensors\xUMVS\src\physics\sitetype.jl

add_operator_fermi(op_inds::Vector{Int64}, sites_ind_prev::Vector{Tuple{Int64, Int64}}, L_prev::ITensor, counter::Int64, element::Vector{Int64}, N::Int64, ops::Tuple{String, String}, s::Vector{Index{Int64}}, ln::Vector{Index{Int64}}, psi::MPS, psi_dag::MPS, C::Dict{Tuple{Vararg{Int64}}, ComplexF64}, indices::Tuple{Int64, Int64}, jw::Int64) at C:\Users\lenovo.julia\packages\ITensorCorrelators\RHiLU\src\correlator_bosonic_recursive.jl

correlator_recursive_compact(psi::MPS, ops::Tuple{String, String}, sites::Vector{Tuple{Int64, Int64}}; indices::Tuple{Int64, Int64}) at C:\Users\lenovo.julia\packages\ITensorCorrelators\RHiLU\src\correlator_bosonic_recursive.jl

kwcall(::NamedTuple{(:indices,), Tuple{Tuple{Int64, Int64}}}, ::typeof(ITensorCorrelators.correlator_recursive_compact), psi::MPS, ops::Tuple{String, String}, sites::Vector{Tuple{Int64, Int64}}) at C:\Users\lenovo.julia\packages\ITensorCorrelators\RHiLU\src\correlator_bosonic_recursive.jl

correlator(psi::MPS, cor_ops::Tuple{String, String}, op_sites::Vector{Tuple{Int64, Int64}}) at C:\Users\lenovo.julia\packages\ITensorCorrelators\RHiLU\src\ITensorCorrelators.jl

top-level scope at c:\Users\lenovo\Desktop\code\test.jl

I have try to use

c = correlator(complex(psio), ("exp2N", "exp3N","exp4N"), [(1, 2, 3)])

but it was not work. Do you have any idea why this occurs?
Thanks in advance for any help,
Yuanyu

2

You should change your definitions from zeros(d, d) to zeros(ComplexF64, d, d). zeros(d, d) implicitly makes a matrix of real values of type Float64.

1 Like
3

Thank you so much, that is work!