qubithubhadamard-test

Estimates the complex expectation value <psi|U|psi> of a unitary operator using quantum interference on an ancilla qubit. The real part is extracted from the default circuit; adding S-dagger before the final Hadamard gives the imaginary part.

Run Cite

Framework: Qiskit
Qubits: 2
Depth: 4
Gate set: H, CU
Licence: Apache-2.0
Version: v1
Updated: 3 hours ago
Runs: 2 completed

Circuit

circuit.py · Qiskit · depth 4

2 completed runs

2 completed runs.

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Suggested citation

@software{qubithub_hadamardtest_2026,
  author = {QubitHub Circuits},
  title = {Hadamard Test},
  year = {2026},
  version = {v1},
  url = {https://qubithub.co/qubithub/hadamard-test},
}

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