Hubbard operators

TensorKitTensors.HubbardOperators.S_minFunction
S_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
S⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the spin-minus operator (only defined for Trivial spin symmetry).

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TensorKitTensors.HubbardOperators.S_min_S_plusFunction
S_min_S_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
S⁻S⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator S⁻S⁺. The only nonzero matrix element corresponds to |↓,↑⟩ <-- |↑,↓⟩.

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TensorKitTensors.HubbardOperators.S_plusFunction
S_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
S⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the spin-plus operator S⁺ = e†_↑ e_↓ (only defined for Trivial spin symmetry).

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TensorKitTensors.HubbardOperators.S_plus_S_minFunction
S_plus_S_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
S⁺S⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator S⁺S⁻. The only nonzero matrix element corresponds to |↑,↓⟩ <-- |↓,↑⟩.

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TensorKitTensors.HubbardOperators.S_xFunction
S_x(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
Sˣ(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the one-body spin-1/2 x-operator on the electrons (only defined for Trivial symmetry). .

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TensorKitTensors.HubbardOperators.S_yFunction
S_y(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
Sʸ(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the one-body spin-1/2 y-operator on the electrons (only defined for Trivial symmetry).

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TensorKitTensors.HubbardOperators.S_zFunction
S_z(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
Sᶻ(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the one-body spin-1/2 z-operator on the electrons.

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TensorKitTensors.HubbardOperators.d_min_d_minFunction
d_min_d_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
d⁻d⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e_{1,↓} e_{2,↓}$ that annihilates a spin-down particle at both sites. The nonzero matrix elements are

    -|0,0⟩ ↤ |↓,↓⟩,     +|0,↑⟩ ↤ |↓,↑↓⟩
    -|↑,0⟩ ↤ |↑↓,↓⟩,    +|↑,↑⟩ ↤ |↑↓,↑↓⟩
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TensorKitTensors.HubbardOperators.d_min_d_plusFunction
d_min_d_plus([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
d⁻d⁺([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator $e_{1,↓}, e†_{2,↓}$ that annihilates a spin-down particle at the first site and creates a spin-down particle at the second.

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TensorKitTensors.HubbardOperators.d_min_u_minFunction
d_min_u_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
d⁻u⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e_{1,↓} e_{2,↑}$ that annihilates a spin-down particle at the first site and a spin-up particle at the second site. The nonzero matrix elements are

    -|0,0⟩ ↤ |↓,↑⟩,     -|0,↓⟩ ↤ |↓,↑↓⟩
    -|↑,0⟩ ↤ |↑↓,↑⟩,    -|↑,↓⟩ ↤ |↑↓,↑↓⟩
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TensorKitTensors.HubbardOperators.d_numFunction
d_num([particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
nꜜ([particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the one-body operator that counts the number of spin-down particles.

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TensorKitTensors.HubbardOperators.d_plus_d_minFunction
d_plus_d_min([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
d⁺d⁻([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator $e†_{1,↓}, e_{2,↓}$ that creates a spin-down particle at the first site and annihilates a spin-down particle at the second.

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TensorKitTensors.HubbardOperators.d_plus_d_plusFunction
d_plus_d_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
d⁺d⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e†_{1,↓} e†_{2,↓}$ that creates a spin-down particle at both sites. The nonzero matrix elements are

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TensorKitTensors.HubbardOperators.d_plus_u_plusFunction
d_plus_u_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
d⁺u⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e†_{1,↓} e†_{2,↑}$ that creates a spin-down particle at the first site and a spin-up particle at the second site.

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TensorKitTensors.HubbardOperators.e_hopFunction
e_hopping([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
e_hop([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator that describes a particle that hops between the first and the second site.

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TensorKitTensors.HubbardOperators.e_min_e_plusFunction
e_min_e_plus([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
e⁻e⁺([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator that annihilates a particle at the first site and creates a particle at the second. This is the sum of u_min_u_plus and d_min_d_plus.

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TensorKitTensors.HubbardOperators.e_numFunction
e_num([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
n([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the one-body operator that counts the number of particles.

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TensorKitTensors.HubbardOperators.e_plus_e_minFunction
e_plus_e_min([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
e⁺e⁻([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator that creates a particle at the first site and annihilates a particle at the second. This is the sum of u_plus_u_min and d_plus_d_min.

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TensorKitTensors.HubbardOperators.hubbard_spaceFunction
hubbard_space(particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the local hilbert space for a Hubbard-type model with the given particle and spin symmetries. The four basis states are

    |0⟩ (vacuum), |↑⟩ = (c↑)†|0⟩, |↓⟩ = (c↓)†|0⟩, |↑↓⟩ = (c↑)†(c↓)†|0⟩.

The possible symmetries are Trivial, U1Irrep, and SU2Irrep, for both particle number and spin.

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TensorKitTensors.HubbardOperators.singlet_minFunction
singlet_min(elt, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
singlet⁻(elt, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the adjoint of singlet_plus operator, which is $(-e_{1,↑} e_{2,↓} + e_{1,↓} e_{2,↑}) / sqrt(2)$

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TensorKitTensors.HubbardOperators.singlet_plusFunction
singlet_plus(elt, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
singlet⁺(elt, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body singlet operator $(e^†_{1,↑} e^†_{2,↓} - e^†_{1,↓} e^†_{2,↑}) / sqrt(2)$, which creates the singlet state when acting on vaccum.

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TensorKitTensors.HubbardOperators.u_min_d_minFunction
u_min_d_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
u⁻d⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e_{1,↑} e_{2,↓}$ that annihilates a spin-up particle at the first site and a spin-down particle at the second site. The nonzero matrix elements are

    -|0,0⟩ ↤ |↑,↓⟩,     +|0,↑⟩ ↤ |↑,↑↓⟩,
    +|↓,0⟩ ↤ |↑↓,↓⟩,    -|↓,↑⟩ ↤ |↑↓,↑↓⟩
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TensorKitTensors.HubbardOperators.u_min_u_minFunction
u_min_u_min(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
u⁻u⁻(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e_{1,↑} e_{2,↑}$ that annihilates a spin-up particle at both sites. The nonzero matrix elements are

    -|0,0⟩ ↤ |↑,↑⟩,     -|0,↓⟩ ↤ |↑,↑↓⟩
    +|↓,0⟩ ↤ |↑↓,↑⟩,    +|↓,↓⟩ ↤ |↑↓,↑↓⟩
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TensorKitTensors.HubbardOperators.u_min_u_plusFunction
u_min_u_plus([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
u⁻u⁺([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator $e_{1,↑}, e†_{2,↑}$ that annihilates a spin-up particle at the first site and creates a spin-up particle at the second.

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TensorKitTensors.HubbardOperators.u_numFunction
u_num([particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
nꜛ([particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the one-body operator that counts the number of spin-up particles.

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TensorKitTensors.HubbardOperators.u_plus_d_plusFunction
u_plus_d_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
u⁺d⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e†_{1,↑} e†_{2,↓}$ that annihilates a spin-up particle at the first site and a spin-down particle at the second site.

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TensorKitTensors.HubbardOperators.u_plus_u_minFunction
u_plus_u_min([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
u⁺u⁻([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the two-body operator $e†_{1,↑}, e_{2,↑}$ that creates a spin-up particle at the first site and annihilates a spin-up particle at the second.

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TensorKitTensors.HubbardOperators.u_plus_u_plusFunction
u_plus_u_plus(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})
u⁺u⁺(elt::Type{<:Number}, particle_symmetry::Type{<:Sector}, spin_symmetry::Type{<:Sector})

Return the two-body operator $e†_{1,↑} e†_{2,↑}$ that creates a spin-up particle at both sites.

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TensorKitTensors.HubbardOperators.ud_numFunction
ud_num([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])
nꜛꜜ([elt::Type{<:Number}], [particle_symmetry::Type{<:Sector}], [spin_symmetry::Type{<:Sector}])

Return the one-body operator that counts the number of doubly occupied sites.

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