Separate normalized and unnormalized objects

src/StatesZoo/StatesZoo.jl

@@ -5,7 +5,10 @@ using QuantumSymbolics, QuantumOpticsBase
 using QuantumSymbolics: withmetadata, @withmetadata, Metadata
 import QuantumSymbolics: express_nolookup
 
-export SingleRailMidSwapBell, DualRailMidSwapBell, ZALMSpinPair
+using LinearAlgebra
+import LinearAlgebra: tr
+
+export SingleRailMidSwapBellW, SingleRailMidSwapBell, DualRailMidSwapBellW, DualRailMidSwapBell, ZALMSpinPairW, ZALMSpinPair, tr
 
 abstract type AbstractTwoQubitState <: QuantumSymbolics.AbstractTwoQubitOp end #For representing density matrices
 Base.show(io::IO, x::AbstractTwoQubitState) = print(io, "$(symbollabel(x))")

src/StatesZoo/single_dual_rail_midswap/single_dual_rail_midswap.jl

@@ -34,7 +34,44 @@
 
 $FIELDS
 
-Generates the spin-spin density matrix for linear photonic entanglement swap 
+Generates the unnormalized spin-spin density matrix for linear photonic entanglement swap 
+with emissive memories emitting single rail photonic qubits from the paper [prajit2023entangling](@cite).
+Since the matrix is 'weighted' by the probability for success, it is suffixed with a W to distinguish it 
+from the normalized object `SingleRailMidSwapBell`.
+It takes the following parameters:
+- eA, eB: Link efficiencies for memories A and B upto the swap (include link loss, detector efficiency, etc.)
+- gA, gB: Memory initialization parameter for memories A and B
+- Pd: Detector dark count probability per photonic mode (assumed to be the same for both detectors)
+- Vis: Interferometer visibility for the midpoint swap' can be complex to account for phase instability
+
+```jldoctest
+julia> r = Register(2)
+
+julia> initialize!(r[1:2], SingleRailMidSwapBellW(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99))
+
+julia> observable(r[1:2], Z⊗Z)
+```
+"""
+@withmetadata struct SingleRailMidSwapBellW <: AbstractTwoQubitState
+    eA::Float64
+    eB::Float64
+    gA::Float64
+    gB::Float64
+    Pd::Float64
+    Vis::Float64
+end
+
+symbollabel(x::SingleRailMidSwapBellW) = "ρˢʳᵐˢᵂ"
+
+
+"""
+$TYPEDEF
+
+Fields:
+
+$FIELDS
+
+Generates the normalized spin-spin density matrix for linear photonic entanglement swap 
 with emissive memories emitting single rail photonic qubits from the paper [prajit2023entangling](@cite)
 It takes the following parameters:
 - eA, eB: Link efficiencies for memories A and B upto the swap (include link loss, detector efficiency, etc.)
@@ -69,7 +106,44 @@
 
 $FIELDS
 
-Generates the spin-spin density matrix for linear photonic entanglement swap with emissive
+Generates the unnormalized spin-spin density matrix for linear photonic entanglement swap with emissive
+ memories emitting dual rail photonic qubits from the paper [prajit2023entangling](@cite). 
+ Since the matrix is 'weighted' by the probability for success, it is suffixed with a W to distinguish it 
+from the normalized object `DualRailMidSwapBell`.
+ It takes the following parameters:
+ - eA, eB: Link efficiencies for memories A and B upto the swap (include link loss, detector efficiency, etc.)
+- gA, gB: Memory initialization parameter for memories A and B 
+- Pd: Detector dark count probability per photonic mode (assumed to be the same for both detectors)
+- Vis: Interferometer visibility for the midpoint swap 
+
+```jldoctest
+julia> r = Register(2)
+
+julia> initialize!(r[1:2], DualRailMidSwapBellW(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99))
+
+julia> observable(r[1:2], Z⊗Z)
+```
+"""
+@withmetadata struct DualRailMidSwapBellW <: AbstractTwoQubitState
+    eA::Float64
+    eB::Float64
+    gA::Float64
+    gB::Float64
+    Pd::Float64
+    Vis::Float64
+end
+
+symbollabel(x::DualRailMidSwapBellW) = "ρᵈʳᵐˢᵂ"
+
+
+"""
+$TYPEDEF
+
+Fields:
+
+$FIELDS
+
+Generates the normalized spin-spin density matrix for linear photonic entanglement swap with emissive
  memories emitting dual rail photonic qubits from the paper [prajit2023entangling](@cite).
  It takes the following parameters:
  - eA, eB: Link efficiencies for memories A and B upto the swap (include link loss, detector efficiency, etc.)
@@ -99,12 +173,27 @@
 
 ## express
 
+function express_nolookup(x::SingleRailMidSwapBellW, ::QuantumOpticsRepr)
+    data = midswap_single_rail(x.eA, x.eB, x.gA, x.gB, x.Pd, x.Vis)
+    return SparseOperator(_bspin⊗_bspin, Complex.(data))
+end
+
 function express_nolookup(x::SingleRailMidSwapBell, ::QuantumOpticsRepr)
     data = midswap_single_rail(x.eA, x.eB, x.gA, x.gB, x.Pd, x.Vis)
+    return SparseOperator(_bspin⊗_bspin, Complex.(data/tr(data)))
+end
+
+function express_nolookup(x::DualRailMidSwapBellW, ::QuantumOpticsRepr)
+    data = midswap_dual_rail(x.eA, x.eB, x.gA, x.gB, x.Pd, x.Vis)
     return SparseOperator(_bspin⊗_bspin, Complex.(data))
 end
 
 function express_nolookup(x::DualRailMidSwapBell, ::QuantumOpticsRepr)
     data = midswap_dual_rail(x.eA, x.eB, x.gA, x.gB, x.Pd, x.Vis)
-    return SparseOperator(_bspin⊗_bspin, Complex.(data))
-end
+    return SparseOperator(_bspin⊗_bspin, Complex.(data/tr(data)))
+end
+
+# Symbolic trace
+
+tr(::SingleRailMidSwapBell) = 1
+tr(::DualRailMidSwapBell) = 1

src/StatesZoo/zalm_pair/zalm_pair.jl

@@ -568,7 +568,59 @@
 
 $FIELDS
 
-Generate symbolic object for the spin-spin density matrix for a 
+Generate symbolic object for the unnormalized spin-spin density matrix for a 
+cascaded source swapped with emissive spin memories. Since the matrix is 'weighted' by the probability for 
+success, it is suffixed with a W to distinguish it from the normalized object `ZALMSpinPair`. The cascaded 
+source from papers [prajit2022heralded](@cite) and [kevin2023zero](@cite) 
+is stored in spin memories as discussed in [prajit2023entangling](@cite).
+It takes the following parameters:
+- Ns: mean photon number per mode of the cascaded source model
+- gA: qubit initialization parameter on Alice's side 
+- gB: qubit initialization parameter on Bob's side 
+- eAm: memory out-coupling efficiency for Alice's side (Allowed range: [0,1])
+- eBm: memory out-coupling efficiency for Bob's side (Allowed range: [0,1])
+- eAs: source out-coupling efficiency for Alice's side (Allowed range: [0,1])
+- eBs: source out-coupling efficiency for Bob's side (Allowed range: [0,1])
+- eD: detector efficiency (Allowed range: [0,1])
+- Pd: dark click probability per photonic mode on source's swap 
+- Pdo1: dark click probability per photonic mode on Alice side swap 
+- Pdo2: dark click probability per photonic mode on Bob side swap
+- VisF: product of visibilities of all three  interferometers (Allowed range: [0,1])
+
+```jldoctest
+julia> r = Register(2)
+
+julia> initialize!(r[1:2], ZALMSpinPairW(1e-3, 0.5, 0.5, 1, 1, 1, 1, 0.9, 1e-8, 1e-8, 1e-8, 0.99))
+
+juilia> observable(r[1:2], Z⊗Z)
+```
+"""
+@withmetadata struct ZALMSpinPairW <: AbstractTwoQubitState
+    Ns::Float64
+    gA::Float64
+    gB::Float64
+    eAm::Float64
+    eBm::Float64
+    eAs::Float64
+    eBs::Float64
+    eD::Float64
+    Pd::Float64
+    Pdo1::Float64
+    Pdo2::Float64
+    VisF::Float64
+end
+
+symbollabel(x::ZALMSpinPairW) = "ρᶻᵃˡᵐᵂ"
+
+
+"""
+$TYPEDEF
+
+Fields:
+
+$FIELDS
+
+Generate symbolic object for the normalized spin-spin density matrix for a 
 cascaded source swapped with emissive spin memories. The cascaded 
 source from papers [prajit2022heralded](@cite) and [kevin2023zero](@cite) 
 is stored in spin memories as discussed in [prajit2023entangling](@cite).
@@ -611,7 +663,17 @@
 
 symbollabel(x::ZALMSpinPair) = "ρᶻᵃˡᵐ"
 
-function express_nolookup(x::ZALMSpinPair, ::QuantumOpticsRepr)
+## express
+
+function express_nolookup(x::ZALMSpinPairW, ::QuantumOpticsRepr)
     data = cascaded_source_spin(x.Ns, x.gA, x.gB, x.eAm, x.eBm, x.eAs, x.eBs, x.eD, x.Pd, x.Pdo1, x.Pdo2, x.VisF)
     return SparseOperator(_bspin⊗_bspin, Complex.(data))
-end
+end
+
+function express_nolookup(x::ZALMSpinPair, ::QuantumOpticsRepr)
+    data = cascaded_source_spin(x.Ns, x.gA, x.gB, x.eAm, x.eBm, x.eAs, x.eBs, x.eD, x.Pd, x.Pdo1, x.Pdo2, x.VisF)
+    return SparseOperator(_bspin⊗_bspin, Complex.(data/tr(data)))
+end
+
+## Symbolic trace 
+tr(::ZALMSpinPair) = 1

test/test_stateszoo_api.jl

@@ -1,15 +1,41 @@
 using QuantumSavory
-using QuantumSavory.StatesZoo: ZALMSpinPair, SingleRailMidSwapBell, DualRailMidSwapBell
+using QuantumSavory.StatesZoo: ZALMSpinPairW, ZALMSpinPair, SingleRailMidSwapBellW, SingleRailMidSwapBell, DualRailMidSwapBellW, DualRailMidSwapBell
+using QuantumOpticsBase
 using Test
 
+zalmW = ZALMSpinPairW(1e-3, 0.5, 0.5, 1, 1, 1, 1, 0.9, 1e-8, 1e-8, 1e-8, 0.99)
+zalm = ZALMSpinPair(1e-3, 0.5, 0.5, 1, 1, 1, 1, 0.9, 1e-8, 1e-8, 1e-8, 0.99)
+srmsW = SingleRailMidSwapBellW(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99)
+srms = SingleRailMidSwapBell(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99)
+drmsW = DualRailMidSwapBellW(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99)
+drms = DualRailMidSwapBell(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99)
+
+r_zalmW = Register(2)
+initialize!(r_zalmW[1:2], zalmW)
+@test ! iszero(observable(r_zalmW[1:2], Z⊗Z))
+
 r_zalm = Register(2)
-initialize!(r_zalm[1:2], ZALMSpinPair(1e-3, 0.5, 0.5, 1, 1, 1, 1, 0.9, 1e-8, 1e-8, 1e-8, 0.99))
+initialize!(r_zalm[1:2], zalm)
 @test ! iszero(observable(r_zalm[1:2], Z⊗Z))
 
+r_srmsW = Register(2)
+initialize!(r_srmsW[1:2], srmsW)
+@test ! iszero(observable(r_srmsW[1:2], Z⊗Z))
+
 r_srms = Register(2)
-initialize!(r_srms[1:2], SingleRailMidSwapBell(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99))
+initialize!(r_srms[1:2], srms)
 @test ! iszero(observable(r_srms[1:2], Z⊗Z))
 
+r_drmsW = Register(2)
+initialize!(r_drmsW[1:2], drmsW)
+@test ! iszero(observable(r_drmsW[1:2], Z⊗Z))
+
 r_drms = Register(2)
-initialize!(r_drms[1:2], DualRailMidSwapBell(0.9, 0.9, 0.5, 0.5, 1e-8, 0.99))
-@test ! iszero(observable(r_drms[1:2], Z⊗Z))
+initialize!(r_drms[1:2], drms)
+@test ! iszero(observable(r_drms[1:2], Z⊗Z))
+
+@test tr(zalm) == tr(express(zalm))
+
+@test tr(srms) == tr(express(srms))
+
+@test tr(drms) == tr(express(drms))