its/reflection.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "CHSH correlation value: -1.438\n"
     ]
    }
   ],
   "source": [
    "import random\n",
    "import numpy as np\n",
    "from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister, transpile\n",
    "from qiskit_aer import Aer\n",
    "from qiskit.circuit.library import HGate, IGate\n",
    "\n",
    "numberOfSinglets = 10000\n",
    "\n",
    "qr = QuantumRegister(2, \"q\")\n",
    "cr = ClassicalRegister(2, \"c\")\n",
    "\n",
    "singlet = QuantumCircuit(qr, cr, name=\"Singlet\")\n",
    "singlet.h(qr[0])\n",
    "singlet.cx(qr[0], qr[1])\n",
    "singlet.x(qr[1])\n",
    "singlet.z(qr[0])\n",
    "\n",
    "prover_operation = IGate()\n",
    "verifier_operation = HGate()\n",
    "\n",
    "x = [random.randint(0, 1) for _ in range(numberOfSinglets)]\n",
    "y = [random.randint(0, 1) for _ in range(numberOfSinglets)]\n",
    "\n",
    "a = [random.randint(0, 1) for _ in range(numberOfSinglets)]\n",
    "\n",
    "\n",
    "def apply_x_measurement_basis(circuit, qubit, basis_choice):\n",
    "    if basis_choice == 1:\n",
    "        circuit.h(qubit)\n",
    "\n",
    "\n",
    "def apply_y_measurement_basis(circuit, qubit, basis_choice):\n",
    "    if basis_choice == 0:\n",
    "        circuit.ry(-np.pi / 4, qubit)\n",
    "    else:\n",
    "        circuit.ry(np.pi / 4, qubit)\n",
    "\n",
    "\n",
    "circuits = []\n",
    "\n",
    "for i in range(numberOfSinglets):\n",
    "    combined_circuit = singlet.copy(name=f\"Singlet_{i}:A{x[i]}_B{y[i]}\")\n",
    "\n",
    "    if a[i] == 1:\n",
    "        combined_circuit = combined_circuit.compose(prover_operation, qubits=[qr[1]])\n",
    "    if a[i] == 1:\n",
    "        combined_circuit = combined_circuit.compose(verifier_operation, qubits=[qr[1]])\n",
    "\n",
    "    apply_x_measurement_basis(combined_circuit, qr[0], x[i])\n",
    "    apply_y_measurement_basis(combined_circuit, qr[1], y[i])\n",
    "\n",
    "    combined_circuit.measure(qr, cr)\n",
    "    circuits.append(combined_circuit)\n",
    "\n",
    "aer_sim = Aer.get_backend(\"aer_simulator\")\n",
    "compiled_circuits = transpile(circuits, aer_sim)\n",
    "job = aer_sim.run(compiled_circuits, shots=1, memory=True)\n",
    "result = job.result()\n",
    "\n",
    "ModeAResults = []\n",
    "ModeBResults = []\n",
    "\n",
    "for i in range(numberOfSinglets):\n",
    "    res = result.get_memory(i)[0]\n",
    "    index = int(res, 2)\n",
    "\n",
    "    if index == 0:\n",
    "        ModeAResults.append(+1)\n",
    "        ModeBResults.append(+1)\n",
    "    elif index == 1:\n",
    "        ModeAResults.append(+1)\n",
    "        ModeBResults.append(-1)\n",
    "    elif index == 2:\n",
    "        ModeAResults.append(-1)\n",
    "        ModeBResults.append(+1)\n",
    "    elif index == 3:\n",
    "        ModeAResults.append(-1)\n",
    "        ModeBResults.append(-1)\n",
    "\n",
    "\n",
    "def chsh_corr(result, x, y, numberOfSinglets):\n",
    "    countA0B0 = [0, 0, 0, 0]\n",
    "    countA0B1 = [0, 0, 0, 0]\n",
    "    countA1B0 = [0, 0, 0, 0]\n",
    "    countA1B1 = [0, 0, 0, 0]\n",
    "\n",
    "    for i in range(numberOfSinglets):\n",
    "        res = result.get_memory(i)[0]\n",
    "        index = int(res, 2)\n",
    "\n",
    "        if x[i] == 0 and y[i] == 0:\n",
    "            countA0B0[index] += 1\n",
    "        elif x[i] == 0 and y[i] == 1:\n",
    "            countA0B1[index] += 1\n",
    "        elif x[i] == 1 and y[i] == 0:\n",
    "            countA1B0[index] += 1\n",
    "        elif x[i] == 1 and y[i] == 1:\n",
    "            countA1B1[index] += 1\n",
    "\n",
    "    def expectation(counts):\n",
    "        total = sum(counts)\n",
    "        if total == 0:\n",
    "            return 0\n",
    "        return (counts[0] - counts[1] - counts[2] + counts[3]) / total\n",
    "\n",
    "    expect00 = expectation(countA0B0)\n",
    "    expect01 = expectation(countA0B1)\n",
    "    expect10 = expectation(countA1B0)\n",
    "    expect11 = expectation(countA1B1)\n",
    "\n",
    "    corr = expect00 + expect01 + expect10 - expect11\n",
    "    return corr\n",
    "\n",
    "\n",
    "corr = chsh_corr(result, x, y, numberOfSinglets)\n",
    "print(\"CHSH correlation value:\", round(corr, 3))"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": ".venv",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.12.9"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}