| name | Qiskit Framework |
| description | Conceptual quantum circuit construction, qubit initialization, gate application, and measurement in Python. |
Qiskit Framework
Qiskit is IBM's open-source SDK for quantum computing. It provides a programmatic abstraction for designing quantum circuits, compiling them for specific architectures, and executing them on simulators or physical QPUs.
Theoretical Foundation & Architecture
Quantum circuits in Qiskit are represented as DAGs (Directed Acyclic Graphs). A QuantumCircuit instance holds QuantumRegister and ClassicalRegister objects. Unitary operations (gates) manipulate the quantum state space $\mathbb{C}^{2^n}$, while measurements collapse the state onto the computational basis, recording outcomes in classical bits.
Actionable Execution
- Initialization: Instantiate
QuantumCircuit(n, m) with $n$ qubits and $m$ classical bits. All qubits initialize to $|0\rangle$.
- Gate Application:
- Apply single-qubit gates (e.g.,
qc.h(0), qc.rx(theta, 0)).
- Apply entangling two-qubit gates (e.g.,
qc.cx(0, 1) for CNOT).
- Measurement: Map quantum states to classical registers (
qc.measure(qubit_index, bit_index)).
- Execution: Transpile the circuit for a target backend and invoke
run().
Execution Flow
flowchart TD
A[Start] --> B[Initialize QuantumCircuit]
B --> C[Allocate Quantum and Classical Registers]
C --> D[Apply Unitary Gates]
D --> E[Apply Entangling Operations]
E --> F[Add Measurement Operations]
F --> G[Transpile Circuit for Backend]
G --> H[Execute on Simulator or QPU]
H --> I[Analyze Results/Counts]
I --> J[End]
