Skip to content

Add Hubbard model #80

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
lkdvos wants to merge 2 commits into from
Closed

Add Hubbard model #80

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c21f2cd
Add utility function `InfiniteSquare`
lkdvos Oct 26, 2024
49a6e22
Add Hubbard model
lkdvos Oct 26, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions src/operators/lattices/squarelattice.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,8 @@ struct InfiniteSquare <: AbstractLattice{2}
end
end

Base.size(lattice::InfiniteSquare) = (lattice.Nrows, lattice.Ncols)

function vertices(lattice::InfiniteSquare)
return CartesianIndices((1:(lattice.Nrows), 1:(lattice.Ncols)))
end
Expand Down
24 changes: 24 additions & 0 deletions src/operators/models.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -122,3 +122,27 @@ function pwave_superconductor(
(neighbor => hy for neighbor in y_neighbors)...,
)
end

function MPSKitModels.hubbard_model(
T::Type{<:Number},
particle_symmetry::Type{<:Sector},
spin_symmetry::Type{<:Sector},
lattice::InfiniteSquare;
t=1.0,
U=1.0,
mu=0.0,
n::Integer=0,
)
@assert n == 0 "Currently no support for imposing a fixed particle number"
hopping =
MPSKitModels.e⁺e⁻(T, particle_symmetry, spin_symmetry) +
MPSKitModels.e⁻e⁺(T, particle_symmetry, spin_symmetry)
interaction_term = MPSKitModels.nꜛnꜜ(T, particle_symmetry, spin_symmetry)
N = MPSKitModels.e_number(T, particle_symmetry, spin_symmetry)

return LocalOperator(
fill(domain(hopping)[1], size(lattice)),
(neighbor => -t * hopping for neighbor in nearest_neighbours(lattice))...,
((idx,) => U * interaction_term - mu * N for idx in vertices(lattice))...,
)
end