Introduction:
Quantum computers work differently than normal computers. They use the properties of quantum physics to perform calculations. Qiskit is a free open-source software library that lets you write and run quantum programs easily. In this basic guide, we will walk through the steps to create a simple quantum program using Qiskit.
Prerequisites:
Before starting, you need to have Python and Qiskit installed on your computer. Qiskit works with Python 3.5 or later. Follow the installation instructions on the Qiskit website to set it up. Some basic knowledge of Python programming is helpful but not required.
Step 1 – Import Qiskit:
First, we import the Qiskit modules we will use in our program. This allows us to access all the functions of Qiskit.
from qiskit import QuantumCircuit, execute, AerStep 2 – Create a quantum circuit:
Next, we create a simple quantum circuit with 1 qubit. The QuantumCircuit class allows us to define a circuit.
circuit = QuantumCircuit(1, 1)Step 3 – Add gates to the circuit:
Now we can add quantum gates to our circuit. Let’s add a Hadamard gate and a measurement.
circuit.h(0)
circuit.measure([0], [0])Step 4 – Run the circuit:
To run the circuit, we use an executor. Aer is a Qiskit simulator that mimics an ideal quantum computer.
simulator = Aer.get_backend('qasm_simulator')
result = execute(circuit, simulator).result()Step 5 – Output the results:
Finally, we can see the output from our circuit by printing the counts.
print(result.get_counts(circuit))This will print either {“0”: 1024} or {“1”: 1024} randomly each time, due to the superposition created by the Hadamard gate.
And we have now created and run our first quantum program with Qiskit! While basic, this shows how the core features of Qiskit work. You can now start building more complex quantum algorithms and circuits.
Summary:
- Imported Qiskit modules
- Created a simple 1 qubit quantum circuit
- Added quantum gates to the circuit
- Ran the circuit on a Qiskit simulator backend
- Printed the output results
Qiskit provides a powerful framework for writing quantum code. With just a few lines of Python, we can leverage quantum computing principles. This intro should give you a sense of how to start programming quantum algorithms using Qiskit.
