Software Sheet — SDK Rosetta Stone & Workflow Recipes (L05, L11–L12, L17) - Quantum Computing & Quantum Information

The Stack¶

Algorithm $\to$ circuit IR $\to$ transpiler (basis gates + routing) $\to$ pulses $\to$ shots.
Portable interchange: OpenQASM 3. Debug order: statevector $\to$ shots $\to$ noise model $\to$ QPU.

Rosetta Stone: Bell Pair¶

Qiskit

from qiskit import QuantumCircuit
qc = QuantumCircuit(2,2)
qc.h(0); qc.cx(0,1); qc.measure_all()

Cirq

q = cirq.LineQubit.range(2)
c = cirq.Circuit([cirq.H(q[0]),
  cirq.CNOT(q[0],q[1]), cirq.measure(*q)])

PennyLane

@qml.qnode(qml.device("default.qubit", wires=2))
def bell():
    qml.Hadamard(0); qml.CNOT(wires=[0,1])
    return qml.probs()

Braket

c = Circuit().h(0).cnot(0,1)

pyQuil

p = Program(H(0), CNOT(0,1))

Simulator Cheat Table¶

Mode	Memory	Captures noise?
Statevector	$2^n$	no
Shot sampler	$2^n$	shot noise
Density matrix	$4^n$	Kraus channels
Stabilizer	poly	Clifford only
Tensor network	entanglement-dep.	limited

Transpilation Checklist (L05)¶

$\square$ Which basis gates?
$\square$ Coupling map / SWAP overhead?
$\square$ Depth before vs. after (optimization level 0–3)?
$\square$ Measured qubits mapped where? (layout matters for readout error)

Materials Pipeline Packages (L11–L12, L17)¶

openfermion / qiskit-nature / pennylane-qchem: molecule or lattice $\to$ second-quantized $H$ $\to$ Jordan–Wigner/BK Pauli sum.
pyscf: classical HF/DFT reference + integrals (active-space selection).
mitiq: ZNE / PEC error mitigation, SDK-agnostic.
Typical VQE skeleton:

H = jordan_wigner(molecular_hamiltonian)
E = minimize(lambda th:
      expval(H, ansatz(th)), th0,
      method="COBYLA")

Reproducibility Habits¶

Pin package versions; log transpiled circuits + backend calibration snapshot with every result; report shots and error bars; seed simulators.
Course notebooks: set backend in the first cell — everything downstream is backend-agnostic.