qcmet.benchmarks.VQE1DFermiHubbard#

class qcmet.benchmarks.VQE1DFermiHubbard(qubits, U=0.0, t=1.0, shift_number=False, save_path=None, **kwargs)[source]#

Variational Quantum Eigensolver implementation for the 1D Fermi-Hubbard model.

This class extends the base VQE class to simulate the ground state energy of the 1D Fermi-Hubbard model using a parameterized ansatz and Jordan-Wigner transformed Hamiltonian.

__init__(qubits, U=0.0, t=1.0, shift_number=False, save_path=None, **kwargs)[source]#

Initialize the VQE1DFermiHubbard instance with model parameters.

Sets up the number of sites, interaction strength, hopping amplitude, and whether to shift the number operator.

Parameters:

  • qubits (int) – Total number of qubits (must be even, representing spin-up and spin-down).

  • U (float) – On-site interaction strength.

  • t (float) – Hopping amplitude between neighboring sites.

  • shift_number (bool) – Whether to shift the number operator to center the interaction.

  • save_path (str | Path | FileManager | None, optional) – Directory path to save results. Defaults to None.

  • **kwargs – Additional configuration parameters passed to the base VQE class.

Raises:

AssertionError – If the number of qubits is not even.

Methods

__init__(qubits[, U, t, shift_number, save_path])

Initialize the VQE1DFermiHubbard instance with model parameters.

analyze()

Analyze measurements to return benchmark results.

generate_circuits()

Generate benchmark circuits, user facing.

get_energy()

Compute the expectation value of the Hamiltonian from shot data.

has_plotting()

Check if _plot function is implemented in benchmark.

load_circuit_measurements(circuit_measurements)

Load measurement counts into the experiment_data DataFrame.

measurements_to_probabilities()

Convert raw measurement counts to normalized probabilities.

plot([axes])

Plot benchmark result, user facing.

run([device, num_shots, max_circs_per_job])

Run benchmark.

save()

Save benchmark current state.

set_save_path(save_path)

Set benchmark save path if not set in class constructor.

statevector_energy()

Compute the expectation value of the Hamiltonian using statevector simulation.

Attributes

circuits

Gets all benchmark circuits.

experiment_data

Getter for experiment_data dataframe.

full_ansatz_circuit

Accessor for the full ansatz circuit (init + layers).

hamiltonian

Return the full Fermi-Hubbard Hamiltonian mapped to qubits via Jordan-Wigner transformation.

initial_state

Prepare the initial Gaussian state corresponding to the non-interacting tight-binding Hamiltonian.

num_qubits

Number of qubits in this benchmark.

variational_parameters

Get or initialize the variational parameters for the ansatz circuit.
property initial_state#

Prepare the initial Gaussian state corresponding to the non-interacting tight-binding Hamiltonian.

Uses OpenFermion’s Gaussian state preparation and converts the Cirq circuit to Qiskit via QASM.

Returns:

The initial state circuit in Qiskit format.

Return type:

QuantumCircuit

property hamiltonian#

Return the full Fermi-Hubbard Hamiltonian mapped to qubits via Jordan-Wigner transformation.

Combines the tight-binding and interaction Hamiltonians.

Returns:

The full Hamiltonian in qubit representation.

Return type:

openfermion.QubitOperator