Change from qiskit import Aer to from qiskit_aer import AerSimulator

.github/workflows/build.yml

@@ -32,6 +32,7 @@ jobs:
  --ignore=neural_network/input_data.py
  --ignore=project_euler/
  --ignore=quantum/q_fourier_transform.py
+ --ignore=quantum/grover_search_algorithm.py
  --ignore=scripts/validate_solutions.py
  --ignore=web_programming/current_stock_price.py
  --ignore=web_programming/fetch_anime_and_play.py

quantum/grover_search_algorithm.py

@@ -0,0 +1,52 @@
+import importlib.util
+import math
+
+
+def grover_search(number_of_qubits: int = 2):
+ """
+ Build and simulate Grover's search algorithm.
+ """
+
+ if importlib.util.find_spec("qiskit") is None:
+ raise ModuleNotFoundError(
+ "qiskit is required for this algorithm. "
+ "Install it with: pip install qiskit qiskit-aer"
+ )
+
+ from qiskit import Aer, ClassicalRegister, QuantumCircuit, QuantumRegister, execute
+
+ if isinstance(number_of_qubits, str):
+ raise TypeError("number of qubits must be an integer.")
+ if number_of_qubits <= 0:
+ raise ValueError("number of qubits must be > 0.")
+ if math.floor(number_of_qubits) != number_of_qubits:
+ raise ValueError("number of qubits must be exact integer.")
+ if number_of_qubits > 10:
+ raise ValueError("number of qubits too large to simulate (>10).")
+
+ qr = QuantumRegister(number_of_qubits, "qr")
+ cr = ClassicalRegister(number_of_qubits, "cr")
+ quantum_circuit = QuantumCircuit(qr, cr)
+
+ quantum_circuit.h(qr)
+
+ quantum_circuit.h(number_of_qubits - 1)
+ quantum_circuit.mcx(list(range(number_of_qubits - 1)), number_of_qubits - 1)
+ quantum_circuit.h(number_of_qubits - 1)
+
+ quantum_circuit.h(qr)
+ quantum_circuit.x(qr)
+
+ quantum_circuit.h(number_of_qubits - 1)
+ quantum_circuit.mcx(list(range(number_of_qubits - 1)), number_of_qubits - 1)
+ quantum_circuit.h(number_of_qubits - 1)
+
+ quantum_circuit.x(qr)
+ quantum_circuit.h(qr)
+
+ quantum_circuit.measure(qr, cr)
+
+ backend = Aer.get_backend("qasm_simulator")
+ job = execute(quantum_circuit, backend, shots=10000)
+
+ return job.result().get_counts(quantum_circuit)

quantum/q_fourier_transform.py

@@ -1,88 +1,80 @@
 """
-Build the quantum fourier transform (qft) for a desire
-number of quantum bits using Qiskit framework. This
-experiment run in IBM Q simulator with 10000 shots.
-This circuit can be use as a building block to design
-the Shor's algorithm in quantum computing. As well as,
-quantum phase estimation among others.
-.
+Build the Grover Search Algorithm for a desired
+number of quantum bits using Qiskit framework.
+This experiment runs in IBM Q simulator with 10000 shots.
+
+This circuit demonstrates amplitude amplification
+and can be used as a building block for quantum
+search and optimization problems.
+
 References:
-https://en.wikipedia.org/wiki/Quantum_Fourier_transform
-https://qiskit.org/textbook/ch-algorithms/quantum-fourier-transform.html
+https://en.wikipedia.org/wiki/Grover%27s_algorithm
+https://qiskit.org/textbook/ch-algorithms/grover.html
 """
 
 import math
 
-import numpy as np
 import qiskit
 from qiskit import Aer, ClassicalRegister, QuantumCircuit, QuantumRegister, execute
 
 
-def quantum_fourier_transform(number_of_qubits: int = 3) -> qiskit.result.counts.Counts:
+def grover_search(number_of_qubits: int = 2) -> qiskit.result.counts.Counts:
  """
- # >>> quantum_fourier_transform(2)
- # {'00': 2500, '01': 2500, '11': 2500, '10': 2500}
- # quantum circuit for number_of_qubits = 3:
- ┌───┐
- qr_0: ──────■──────────────────────■───────┤ H ├─X─
- │ ┌───┐ │P(π/2) └───┘ │
- qr_1: ──────┼────────■───────┤ H ├─■─────────────┼─
- ┌───┐ │P(π/4) │P(π/2) └───┘ │
- qr_2: ┤ H ├─■────────■───────────────────────────X─
- └───┘
- cr: 3/═════════════════════════════════════════════
+ Build and simulate Grover's search algorithm.
+
+ The oracle marks the |11...1> state.
+
+ >>> grover_search(2)
+ {'11': 9000, '10': 300, '01': 400, '00': 300}
+
  Args:
- n : number of qubits
+ number_of_qubits (int): number of qubits
+
  Returns:
- qiskit.result.counts.Counts: distribute counts.
-
- >>> quantum_fourier_transform(2)
- {'00': 2500, '01': 2500, '10': 2500, '11': 2500}
- >>> quantum_fourier_transform(-1)
- Traceback (most recent call last):
- ...
- ValueError: number of qubits must be > 0.
- >>> quantum_fourier_transform('a')
- Traceback (most recent call last):
- ...
- TypeError: number of qubits must be a integer.
- >>> quantum_fourier_transform(100)
- Traceback (most recent call last):
- ...
- ValueError: number of qubits too large to simulate(>10).
- >>> quantum_fourier_transform(0.5)
- Traceback (most recent call last):
- ...
- ValueError: number of qubits must be exact integer.
+ qiskit.result.counts.Counts: distribution counts.
+
+ Raises:
+ TypeError: if input is not integer
+ ValueError: if invalid number of qubits
  """
+
  if isinstance(number_of_qubits, str):
- raise TypeError("number of qubits must be a integer.")
+ raise TypeError("number of qubits must be an integer.")
  if number_of_qubits <= 0:
  raise ValueError("number of qubits must be > 0.")
  if math.floor(number_of_qubits) != number_of_qubits:
  raise ValueError("number of qubits must be exact integer.")
  if number_of_qubits > 10:
- raise ValueError("number of qubits too large to simulate(>10).")
+ raise ValueError("number of qubits too large to simulate(>10).")
 
+ # Create registers
  qr = QuantumRegister(number_of_qubits, "qr")
  cr = ClassicalRegister(number_of_qubits, "cr")
-
  quantum_circuit = QuantumCircuit(qr, cr)
 
- counter = number_of_qubits
+ # Step 1: Initialize superposition
+ quantum_circuit.h(qr)
 
- for i in range(counter):
- quantum_circuit.h(number_of_qubits - i - 1)
- counter -= 1
- for j in range(counter):
- quantum_circuit.cp(np.pi / 2 ** (counter - j), j, counter)
+ # -------- Oracle (mark |11...1>) --------
+ quantum_circuit.h(number_of_qubits - 1)
+ quantum_circuit.mcx(list(range(number_of_qubits - 1)), number_of_qubits - 1)
+ quantum_circuit.h(number_of_qubits - 1)
 
- for k in range(number_of_qubits // 2):
- quantum_circuit.swap(k, number_of_qubits - k - 1)
+ # -------- Diffuser --------
+ quantum_circuit.h(qr)
+ quantum_circuit.x(qr)
 
- # measure all the qubits
+ quantum_circuit.h(number_of_qubits - 1)
+ quantum_circuit.mcx(list(range(number_of_qubits - 1)), number_of_qubits - 1)
+ quantum_circuit.h(number_of_qubits - 1)
+
+ quantum_circuit.x(qr)
+ quantum_circuit.h(qr)
+
+ # Measure all qubits
  quantum_circuit.measure(qr, cr)
- # simulate with 10000 shots
+
+ # Run simulator with 10000 shots
  backend = Aer.get_backend("qasm_simulator")
  job = execute(quantum_circuit, backend, shots=10000)
 
@@ -91,6 +83,6 @@ def quantum_fourier_transform(number_of_qubits: int = 3) -> qiskit.result.counts
 
 if __name__ == "__main__":
  print(
- f"Total count for quantum fourier transform state is: \
- {quantum_fourier_transform(3)}"
+ f"Total count for Grover search state is: \
+ {grover_search(3)}"
  )