qrisp.multi_measurement#

multi_measurement(qv_list, shots=None, backend=None)[source]#

This functions facilitates the measurement of multiple QuantumVariables at the same time. This can be used if the entanglement structure between several QuantumVariables is of interest.

Parameters:

qv_listlist[QuantumVariable]: A list of QuantumVariables.
shotsint, optional: The amount of shots to perform. The default is given by the backend used.
backendBackendClient, optional: The backend to evaluate the compiled QuantumCircuit on. By default, the backend from default_backend.py will be used.

Returns:

counts_listlist: A list of tuples. The first element of each tuple is a tuple again and contains the labels of the QuantumVariables. The second element is a float and indicates the probability of measurement.

Raises:

Exception: Tried to perform measurement with open environments.

Examples

We entangle three QuantumFloats via addition and perform a multi-measurement:

>>> from qrisp import QuantumFloat, h, multi_measurement
>>> qf_0 = QuantumFloat(4)
>>> qf_1 = QuantumFloat(4)
>>> qf_0[:] = 3
>>> qf_1[:] = 2
>>> h(qf_1[0])
>>> qf_sum = qf_0 + qf_1
>>> multi_measurement([qf_0, qf_1, qf_sum])
{(3, 2, 5): 0.5, (3, 3, 6): 0.5}