Quantum processor crosstalk mitigation using QubiC controller aided by NERSC HPC*

Lawrence Berkeley National Laboratory (LBNL) is developing a quantum ecosystem to enhance public quantum information science research. A superconducting quantum chip developed by the Quantum Nanoelectronics Laboratory at UC, Berkeley has been made available for user experiments through the Advanced Quantum Testbed (AQT). As part of this effort, the Qubit Control (QubiC) system has been developed to manipulate and measure the quantum processors allowing users to implement advanced quantum algorithms through an open-source Python-based application programming interface. Quantum Benchmark Inc. developed a crosstalk mitigation protocol and partnered with AQT to evaluate it on the gate-based quantum chip controlled by the QubiC. The hybrid quantum-classical protocol requires sizable classical computational resources to implement a single-pass optimization which has been offloaded to Cori, a high-performance computer (HPC) at NERSC (National Energy Research Scientific Computing Center). We will overview the QubiC interface, discuss the challenges to execute a heterogeneous quantum-classical algorithm, and also present the quantum gates fidelity improvement achieved from this crosstalk mitigation protocol.