From 3c2e8687febe9d6cb92eac91ce4436d369665e68 Mon Sep 17 00:00:00 2001
From: Jerry Jiang <jiangzhilin1995@gmail.com>
Date: Thu, 23 May 2019 19:01:29 -0700
Subject: [PATCH] #3, #4: Implement entanglement/disentanglement and tests

---
 entangle.py | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 entangle.py

diff --git a/entangle.py b/entangle.py
new file mode 100644
index 0000000..1c187ae
--- /dev/null
+++ b/entangle.py
@@ -0,0 +1,83 @@
+from typing import List
+import numpy as np
+
+import random
+
+from pyquil import Program
+from pyquil.gates import X, H, CNOT
+from pyquil.quil import address_qubits
+from pyquil.quilatom import QubitPlaceholder
+from pyquil.api import QVMConnection
+from pyquil.api import WavefunctionSimulator
+
+
+""" Initialize list of qubits to pure |1> state.
+
+    @param  p (List[QubitPlaceholder]): list of qubits in pure |0> state.
+    @return pq (Program): corresponding PyQuil Program.
+"""
+def init_p(p: List[QubitPlaceholder], noise=None) -> Program:
+    pq = Program()
+    for i in range(len(p)):
+        pq += X(p[i])
+    return pq
+
+
+""" Entangles phi with a series of signal particles.
+
+    @param  phi (QubitPlaceholder): qubit containing transformed version
+                                    of the original secret.
+    @param  p (List[QubitPlaceholder]): single particle pure |1> qubits.
+    @return pq (Program): corresponding PyQuil Program.
+"""
+def entangle(phi: QubitPlaceholder, p: List[QubitPlaceholder],
+             noise=None) -> Program:
+    pq = Program()
+    pq += H(phi)
+    for i in range(len(p)):
+        pq += CNOT(phi, p[i])
+    return pq
+
+
+""" Disentangles the entangled state consisting of phi and a list of particles.
+
+    @param  phi (QubitPlaceholder): entangled secret qubit.
+    @param  p (List[QubitPlaceholder]): entangled single particle qubits.
+    @return pq (Program): corresponding PyQuil Program.
+"""
+def disentangle(phi: QubitPlaceholder, p: List[QubitPlaceholder],
+                noise=None) -> Program:
+    pq = Program()
+    for i in range(len(p)):
+        pq += CNOT(phi, p[i])
+    pq += H(phi)
+    return pq
+
+
+""" Simple tests demonstrating qubit entanglement/disentanglement workloads.
+
+    @param  n (int): number of single particle qubits (p_0,...,p_{n-1}).
+"""
+def entangle_test(n=5):
+    phi = QubitPlaceholder()
+    p = [QubitPlaceholder() for i in range(n)]
+
+    test_pqs = [
+        init_p(p) + entangle(phi, p),
+        init_p(p) + entangle(phi, p) + disentangle(phi, p),
+        init_p(p) + H(phi) + entangle(phi, p),
+        init_p(p) + H(phi) + entangle(phi, p) + disentangle(phi, p),
+    ]
+
+    wf_sim = WavefunctionSimulator()
+    for pq in test_pqs:
+        print(wf_sim.wavefunction(address_qubits(pq)))
+
+
+def main():
+    entangle_test()
+
+
+if __name__ == '__main__':
+    main()
+