Integration Weights Extension Option

The SHFQC-16W Integration Weights Extension option increases the readout capability of the SHFQC Qubit Controller readout channel. If the SHFQC is interfaced with other instruments of the Quantum Computing Control System (QCCS), such as the SHFSG, to control and address a large-scale setup, this option enables reliable discrimination of up to 16 qubits, 8 qutrits or 5 ququads coupled to the same readout line. For a standalone SHFQC instrument, as may be featured in a smaller-scale system, the SHFQC-16W makes it possible to read out and feedback on 6 qutrits or 5 ququads in real time.

With the doubling of the integration weights from 8 to 16, 16 matched filters can be defined to analyze the response of an equal number of readout signals on one line.

The same extension of the number of waveform memory blocks from 8 to 16 in the arbitrary waveform generator enables the generation of the corresponding readout signals for all qubits, qutrits or ququads. Thanks to the time-staggered readout capability of the quantum analyzer channel, all 16 readouts can then be triggered independently.

Even when analyzing 8 qubits or fewer, the SHFQC-16W Integration Weights Extension option effectively doubles the available waveform and matched filter memory per readout signal. This affords more flexibility to optimize qubit readout: for example, users can implement algorithms that include resonator reset pulses to achieve faster readout or readout with lower crosstalk.