Learn QISKIT with Real Code Examples
Updated Nov 25, 2025
Code Sample Descriptions
1
Qiskit Simple Quantum Circuit
from qiskit import QuantumCircuit, Aer, execute
# Create a 2-qubit quantum circuit
qc = QuantumCircuit(2, 2)
# Apply a Hadamard gate to qubit 0
qc.h(0)
# Apply CNOT gate
qc.cx(0, 1)
# Measure qubits
qc.measure([0,1], [0,1])
# Execute on simulator
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Result:', counts)
A minimal Qiskit example creating a 2-qubit quantum circuit, applying a Hadamard gate, and measuring the qubits.
2
Qiskit Bell State Circuit
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(2,2)
qc.h(0)
qc.cx(0,1)
qc.measure([0,1],[0,1])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Bell state counts:', counts)
Creating a Bell state (entangled qubits) and measuring the result.
3
Qiskit GHZ State Circuit
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(3,3)
qc.h(0)
qc.cx(0,1)
qc.cx(0,2)
qc.measure([0,1,2],[0,1,2])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('GHZ state counts:', counts)
Creating a 3-qubit GHZ state and measuring all qubits.
4
Qiskit Superposition Example
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(1,1)
qc.h(0)
qc.measure(0,0)
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Superposition counts:', counts)
Creating a superposition on a single qubit using Hadamard gate.
5
Qiskit Quantum Teleportation Circuit
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(3,3)
qc.h(1)
qc.cx(1,2)
qc.cx(0,1)
qc.h(0)
qc.measure([0,1],[0,1])
qc.cx(1,2)
qc.cz(0,2)
qc.measure(2,2)
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Teleportation result:', counts)
Minimal example of quantum teleportation using 3 qubits.
6
Qiskit Quantum Phase Estimation
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(3,3)
qc.h([0,1,2])
qc.cx(2,0)
qc.cx(1,0)
qc.cx(0,0)
qc.measure([0,1,2],[0,1,2])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Phase estimation counts:', counts)
Illustrates a simple quantum phase estimation setup.
7
Qiskit Grover's Search Algorithm Example
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(2,2)
qc.h([0,1])
qc.cz(0,1)
qc.h([0,1])
qc.measure([0,1],[0,1])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Grover search counts:', counts)
Minimal Grover's algorithm with 2 qubits.
8
Qiskit Deutsch-Jozsa Algorithm Example
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(2,1)
qc.h([0,1])
qc.cz(0,1)
qc.h(0)
qc.measure(0,0)
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('Deutsch-Jozsa result:', counts)
Implementing a simple Deutsch-Jozsa algorithm with 2 qubits.
9
Qiskit Quantum Fourier Transform Example
from qiskit import QuantumCircuit, Aer, execute
import numpy as np
qc = QuantumCircuit(2,2)
qc.h(0)
qc.cp(np.pi/2, 0, 1)
qc.h(1)
qc.measure([0,1],[0,1])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('QFT result:', counts)
Minimal 2-qubit QFT demonstration.
10
Qiskit Variational Quantum Eigensolver (VQE) Example
from qiskit import QuantumCircuit, Aer, execute
qc = QuantumCircuit(2,2)
qc.h(0)
qc.cx(0,1)
qc.rx(0.5,0)
qc.ry(1.2,1)
qc.measure([0,1],[0,1])
simulator = Aer.get_backend('qasm_simulator')
result = execute(qc, simulator).result()
counts = result.get_counts()
print('VQE result:', counts)
Minimal VQE circuit for demonstration.