Automatic general estimator creation

[dchung0741]

In this PR, we introduce the new GeneralEstimator object. It is a callable dataclass that holds all

• QuantumEstimator
• ConcurrentQuantumEstimator
• ParametricQuantumEstimator
• ConcurrentParametricQuantumEstimator

and performs expectation value estimation for generic input argument.

Creation:

Two functions are provided to create a general estimator from (concurrent) estimators automatically

• create_general_estimator_from_estimator
• create_general_estimator_from_concurrent_estimator

Usage: Create a general estimator that performs sampling estimation

# create general estimator from a sampling estimator
sampling_estimator = create_sampling_estimator(...)
general_estimator = create_general_estimator_from_estimator(sampling_estimator)

# operator
op1 = Operator({pauli_label("X0 Z1"): 1, PAULI_IDENTITY: 8 + 9j})
op2 = pauli_label("Z0 Z1")

# state
state_1 = quantum_state(n_qubits = 2, bits = 1)
state_2 = quantum_state(n_qubits = 2, bits = 2)

param_circuit = LinearMappedUnboundParametricQuantumCircuit(2)
theta = param_circuit.add_parameter("theta")
param_circuit.add_ParametricRX_gate(0, theta)
param_state = quantum_state(n_qubits = 2, circuit = param_circuit)


# estimate
general_estimator(op1, state1)

# concurrent estimate
general_estimator(op1, [state1, state2])
general_estimator([op1], [state1, state2])
general_estimator([op1, op2], state1)
general_estimator([op1, op2], [state1])
general_estimator([op1, op2], [state1, state2])

# parametric estimate
general_estimator(op1, param_state, [1, 2, 3])


# concurrent parametric estimate
general_estimator(op1, param_state, [[1, 2, 3], [4, 5, 6]])

Other related functions

• create_concurrent_parametric_estimator_from_concurrent_estimator
• create_parametric_estimator_from_concurrent_estimator
• create_concurrent_estimator_from_estimator
• create_estimator_from_concurrent_estimator

[github-actions]

🚀 Deployed on https://deploy-preview-293--quri-parts.netlify.app