Superconducting Instrumentation for Precision Measurement and Control

A. V. Filimonov

Lihua Sun, Futian Liang, Jin Lin +4 more

Superconducting quantum computers (SQCs) can solve some specific problems which are deeply believed to be intractable for classical computers. One of the key components of SQCs is a high-precision synchronous control system which consists of arbitrary waveform generators (AWGs) and an array of digitizers. Here, we propose a scalable, self-adaptive, synchronous triggering system which allows the synchronization of dozens of qubits with jitters of around 3 ps. The system achieves better phase noise performance than the commercial instruments we tested. Using this scheme, we have successfully implemented the synchronous control and measurement of all the qubits on a 23-qubit quantum processor.

R.A. Kamper

John M. Myers, F. Hadi Madjid

Ambiguity int he contact between laboratory instruments and equations of quantum mechanics is formulated in terms of responses of the instruments to commands transmitted to them by a Classical digital Process-control Computer (CPC); in this way instruments are distinguished from quantum- mechanical models (sets of equations) that specify what is desired of the instruments. Results include: (1) a formulation of quantum mechanics adapted to computer- controlled instruments; (2) a lower bound on the precision of unitary transforms required for quantum searching and a lower bound on sample size needed to show that instruments implement a desired model at that precision; (3) a lower bound on precision of timing required of a CPC in directing instruments; (4) a demonstration that guesswork is necessary in ratcheting up the precision of commands.

James Edward Zimmerman

BOVE, LEONARDO

This thesis presents the development of a superconducting qubit control and readout system based on FPGA technology, with a focus on the design of a pulse sequencer and the integration of frequency-multiplexed control. The system leverages the Quantum Instrumentation Control Kit (QICK), an open-source Xilinx RFSoC-based platform capable of direct digital synthesis and acquisition of microwave signals up to 10 GHz. The QICK firmware was extended to support the simultaneous generation and readout of multiple frequency-multiplexed tones, enabling the control and measurement of several qubits coupled to a shared feedline. This approach optimizes the number of controllable qubits relative to the available ADC and DAC resources on the RFSoC 4x2 board. Furthermore, this work includes the development of Qubase, a Python-based pulse sequencer that allows users to easily define and execute complex sequences of control and measurement pulses through the QICK Python interface. The resulting architecture is both flexible and scalable, providing a foundation for efficient multi-qubit experiments and enabling advanced techniques such as quantum error correction and real-time feedback.