using PauliPropagation
using Base.Threads
using Plots
IBM_mitigated_vals = [1.01688859, 1.00387483, 0.95615886, 0.95966435, 0.83946763,
0.81185907, 0.54640995, 0.45518584, 0.19469377, 0.01301832,0.01016334]
IBM_angles = [0. , 0.1 , 0.2 , 0.3 , 0.4 , 0.5 , 0.6 , 0.7 , 0.8 , 1. , 1.5707]
tn_vals = [9.99999254e-01, 9.99593653e-01, 9.95720077e-01, 9.88301532e-01,
9.78553511e-01, 9.58023054e-01, 9.21986059e-01, 8.81726079e-01,
8.49816779e-01, 8.24900527e-01, 7.91257641e-01, 7.37435202e-01,
6.68573798e-01, 5.88096040e-01, 4.81874079e-01, 3.50316579e-01,
2.26709331e-01, 1.39724659e-01, 7.86639143e-02, 4.24124371e-02,
1.90595136e-02, 6.18879050e-03, -8.27168956e-04, -4.63372099e-03,
-7.05202121e-03, -7.68387421e-03, -6.33121142e-03, -4.32594440e-03,
6.52050191e-04, 1.72598340e-04, 5.64696020e-05, -7.70582375e-07]
tn_angles = LinRange(0, π/2, length(tn_vals));
google_vals = [1, 0.9957248494988796,0.9785691808859784,0.9227771228638144,0.8549387301071374,
0.7790027681081058,0.6093954499261214,0.4257824480390532,0.2090085348069826,0.0116245678393245, -4.8872551798147e-09]
google_angles = [0.000, 0.100, 0.200, 0.300, 0.400,0.500,0.600,0.700,0.800,1.000,1.571]
function kickedisingcircuit(nq, nl; topology=nothing)
# just in case a topology is not provided
if isnothing(topology)
topology = bricklayertopology(nq)
end
# define a layer of parametrized Rx-gates
xlayer(circuit) = append!(circuit, (PauliRotation([:X], [qind]) for qind in 1:nq))
# define a layer of fixed RZZ(π/2)-gates
zzlayer(circuit) = append!(circuit, (PauliRotation([:Z, :Z], pair, -π/2) for pair in topology))
# define the empty circuit
circuit = Gate[]
# append to the circuit
for _ in 1:nl
xlayer(circuit)
zzlayer(circuit)
end
return circuit
end
kickedisingcircuit (generic function with 1 method)
# number of qubits
nq = 127
# the IBM Eagle topology
topology = ibmeagletopology
# 20 layers for the hardest simulation
nl = 20
# create the circuit
circuit = kickedisingcircuit(nq, nl; topology);
# count the number of parameters. Here only the RX gates, the RZZ are frozen to π/2
nparams = countparameters(circuit)
# define the observable (note the index is 62 if you start with 0)
pstr = PauliString(nq, :Z, 63)
PauliString(nqubits: 127, 1.0 * IIIIIIIIIIIIIIIIIIII...)
# perform one simulation
# the reason we make this into a function is so that the Julia garbage collector gets rid of `psum` after we leave the function
# otherwise it floats around in the global name space and takes up RAM
function onesimulation(circuit, pstr, thetas; min_abs_coeff=0, max_weight=Inf)
# propagate
psum = propagate(circuit, pstr, thetas; min_abs_coeff, max_weight)
# overlap with the zero-state
return overlapwithzero(psum)
end
onesimulation (generic function with 1 method)
# set the truncations
min_abs_coeff = 1e-4
max_weight = 8
# prepare everything and run
x_angles = LinRange(0, π/2, 20)
expectations = zeros(length(x_angles))
# multi-thread over the different x_angles
t = @timed @threads for ii in eachindex(x_angles)
angle = x_angles[ii]
thetas = ones(nparams) * angle
@time expectations[ii] = onesimulation(circuit, pstr, thetas; min_abs_coeff, max_weight)
end
print("Total simulation time: ", t.time, " seconds")
2.629244 seconds (2.21 M allocations: 107.480 MiB, 11.93% gc time, 99.86% compilation time)
0.011001 seconds (21.07 k allocations: 839.883 KiB)
0.049489 seconds (21.09 k allocations: 1014.234 KiB)
0.167682 seconds (21.23 k allocations: 1.640 MiB)
0.455618 seconds (21.24 k allocations: 2.100 MiB)
0.925021 seconds (21.28 k allocations: 3.262 MiB)
1.670065 seconds (21.34 k allocations: 6.151 MiB)
3.972723 seconds (21.48 k allocations: 5.515 MiB)
7.596836 seconds (21.71 k allocations: 18.349 MiB)
5.663471 seconds (21.59 k allocations: 13.215 MiB)
6.854871 seconds (21.67 k allocations: 18.347 MiB)
7.023549 seconds (21.67 k allocations: 18.339 MiB, 0.30% gc time)
6.296335 seconds (21.63 k allocations: 18.330 MiB)
1.649338 seconds (21.34 k allocations: 5.507 MiB)
1.169835 seconds (21.32 k allocations: 5.505 MiB)
0.449324 seconds (21.25 k allocations: 2.941 MiB)
0.177397 seconds (21.24 k allocations: 1.979 MiB)
0.073652 seconds (21.21 k allocations: 1.138 MiB)
0.013411 seconds (21.08 k allocations: 860.570 KiB)
0.003127 seconds (21.05 k allocations: 819.789 KiB)
Total simulation time: 47.908874864
seconds
pl = plot(xlabel="θ_x Angle", ylabel="⟨Z62⟩")
plot!(tn_angles, tn_vals, label="Flatiron Tensor Network", color="black", linewidth=3)
plot!(google_angles, google_vals, label="Google Lightcone Statevector", color="grey", linewidth=3)
plot!(x_angles, expectations, marker=:circle, label="Pauli Propagation", linewidth=3, color="royalblue")
scatter!(IBM_angles, IBM_mitigated_vals, label="IBM Quantum Computer", color="Red", ms=4)
