qiskit.pulse.builder.measure

measure(qubits, registers=None)

Measure a qubit within the currently active builder context.

At the pulse level a measurement is composed of both a stimulus pulse and an acquisition instruction which tells the systems measurement unit to acquire data and process it. We provide this measurement macro to automate the process for you, but if desired full control is still available with acquire() and play().

To use the measurement it is as simple as specifying the qubit you wish to measure:

from qiskit import pulse
from qiskit.test.mock import FakeOpenPulse2Q

backend = FakeOpenPulse2Q()

qubit = 0

with pulse.build(backend) as pulse_prog:
    # Do something to the qubit.
    qubit_drive_chan = pulse.drive_channel(0)
    pulse.play(pulse.Constant(100, 1.0), qubit_drive_chan)
    # Measure the qubit.
    reg = pulse.measure(qubit)

For now it is not possible to do much with the handle to reg but in the future we will support using this handle to a result register to build up ones program. It is also possible to supply this register:

with pulse.build(backend) as pulse_prog:
    pulse.play(pulse.Constant(100, 1.0), qubit_drive_chan)
    # Measure the qubit.
    mem0 = pulse.MemorySlot(0)
    reg = pulse.measure(qubit, mem0)

assert reg == mem0

Note

Requires the active builder context to have a backend set.

Parameters

• qubits (Union[List[int], int]) – Physical qubit to measure.

• registers (Union[List[NewType()(StorageLocation, Union[MemorySlot, RegisterSlot])], NewType()(StorageLocation, Union[MemorySlot, RegisterSlot]), None]) – Register to store result in. If not selected the current behavior is to return the MemorySlot with the same index as qubit. This register will be returned.

Return type

Union[List[NewType()(StorageLocation, Union[MemorySlot, RegisterSlot])], NewType()(StorageLocation, Union[MemorySlot, RegisterSlot])]

Returns

The register the qubit measurement result will be stored in.