zerofield

docs/src/advanced/meanfield.md

@@ -10,14 +10,14 @@ Schematically the process is as follows:
 ```julia
 julia> model_0 = hopping(1); # a possible non-interacting model
 
-julia> model_1 = @onsite((i; Φ = meanfield()) --> Φ[i]);
+julia> model_1 = @onsite((i; Φ = zerofield) --> Φ[i]);
 
-julia> model_2 = @hopping((i, j; Φ = meanfield()) -> Φ[i, j]);Fock
+julia> model_2 = @hopping((i, j; Φ = zerofield) -> Φ[i, j]);Fock
 
 julia> h = lat |> hamiltonian(model_0 + model_1 + model_2)
 ```
 Here `model_1` corresponds to Hartree and onsite-Fock mean field terms, while `model_2` corresponds to inter-site Fock terms.
-The default value `Φ = meanfield()` is a `ZeroMeanField` object that represents no interactions, so `model_1` and `model_2` vanish by default.
+The default value `Φ = zerofield` is an singleton object that represents no interactions, so `model_1` and `model_2` vanish by default.
 - We build the `GreenFunction` of `h` with `g = greenfunction(h, solver; kw...)` using the `GreenSolver` of choice
 - We construct a `M::MeanField` object using `M = meanfield(g; potential = pot, other_options...)`
 
@@ -74,7 +74,7 @@ With the serializer functionality we can build a version of the fixed-point func
 ```julia
 julia> using SIAMFANLEquations
 
-julia> h = LP.linear() |> supercell(4) |> onsite(r->r[1]) - hopping(1) + @onsite((i; phi = meanfield()) --> phi[i]);
+julia> h = LP.linear() |> supercell(4) |> onsite(r->r[1]) - hopping(1) + @onsite((i; phi = zerofield) --> phi[i]);
 
 julia> M = meanfield(greenfunction(h); onsite = 1, selector = (; range = 0), fock = nothing)
 MeanField{ComplexF64} : builder of Hartree-Fock mean fields
@@ -132,7 +132,7 @@ julia> using SIAMFANLEquations
 
 julia> h = LP.linear() |> supercell(4) |> supercell |> onsite(1) - hopping(1) + @onsite((i; phi) --> phi[i]);
 
-julia> M´(phi = meanfield()) = meanfield(greenfunction(h(; phi), GS.Spectrum()); onsite = 1, selector = (; range = 0), fock = nothing)
+julia> M´(phi = zerofield) = meanfield(greenfunction(h(; phi), GS.Spectrum()); onsite = 1, selector = (; range = 0), fock = nothing)
 M´ (generic function with 3 methods)
 
 julia> Φ0 = M´()(0.0, 0.0);

src/Quantica.jl

@@ -33,7 +33,7 @@ export sublat, bravais_matrix, lattice, sites, supercell, hamiltonian,
        conductance, josephson, ldos, current, transmission, densitymatrix,
        OrbitalSliceArray, OrbitalSliceVector, OrbitalSliceMatrix, orbaxes, siteindexdict,
        serializer, serialize, serialize!, deserialize!, deserialize,
-       meanfield
+       meanfield, zerofield
 
 export LatticePresets, LP, RegionPresets, RP, HamiltonianPresets, HP, ExternalPresets, EP
 export EigenSolvers, ES, GreenSolvers, GS

src/docstrings.jl

@@ -2602,10 +2602,10 @@ interaction potentials, and `ρ` is the density matrix evaluated at specific che
 potential and temperature. Also `ν = ifelse(nambu, 0.5, 1.0)`, and `v_F(0) = v_H(0) = U`,
 where `U` is the onsite interaction.
 
-    meanfield()
+    zerofield
 
-Build an `M::ZeroMeanField` object that represents a zero-values mean field. It has the
-property that it returns zero no matter how it is indexed (`M[inds...] = 0.0 * I`), so it is
+An sigleton of type `ZeroField` that represents a zero-values field. It has the property
+that it returns zero no matter how it is indexed (`zerofield[inds...] = 0.0 * I`), so it is
 useful as a default value in a non-spatial model involving mean fields.
 
 ## Keywords
@@ -2631,7 +2631,7 @@ e.g. `ϕ[sites(2:3), sites(1)]`, see `OrbitalSliceArray` for details.
 # Examples
 
 ```jldoctest
-julia> model = hopping(I) - @onsite((i; phi = meanfield()) --> phi[i]);
+julia> model = hopping(I) - @onsite((i; phi = zerofield) --> phi[i]);
 
 julia> g = LP.honeycomb() |> hamiltonian(model, orbitals = 2) |> supercell((1,-1)) |> greenfunction;
 

src/meanfield.jl

@@ -17,7 +17,7 @@ struct MeanField{B,T,S<:SparseMatrixCSC,H<:DensityMatrix,F<:DensityMatrix}
     onsite_tmp::Vector{Complex{T}}
 end
 
-struct ZeroMeanField end
+struct ZeroField end
 
 #region ## Constructors ##
 
@@ -120,13 +120,13 @@ function (m::MeanField{B})(args...; chopsmall = true, params...) where {B}
 end
 
 
-## ZeroMeanField
+## ZeroField
 
-meanfield() = ZeroMeanField()
+const zerofield = ZeroField()
 
-(m::ZeroMeanField)(args...; kw...) = m
+(m::ZeroField)(args...; kw...) = m
 
-Base.getindex(::ZeroMeanField, _...) = 0.0 * I
+Base.getindex(::ZeroField, _...) = 0.0 * I
 
 #endregion
 

test/test_hamiltonian.jl

@@ -158,7 +158,7 @@ end
     @test_throws ArgumentError h()
 
     # out of bounds indexing
-    h = LP.linear() |>  @hopping((i,j; phi = missing) --> phi[i, j]);
+    h = LP.linear() |>  @hopping((i,j; phi = zerofield()) --> phi[i, j]);
     ϕ = h[cells = 0]
     @test h(phi = ϕ) isa Hamiltonian
 end