Summary: Chicago Quantum Exchange (CQE) Pulse-level Quantum Control Workshop

Abstract

Quantum information processing holds great promise for pushing beyond the current frontiers in computing. Specifically, quantum computation promises to accelerate the solving of certain problems, and there are many opportunities for innovation based on applications in chemistry, engineering, and finance. To harness the full potential of quantum computing, however, we must not only place emphasis on manufacturing better qubits, advancing our algorithms, and developing quantum software. To scale devices to the fault tolerant regime, we must refine device-level quantum control.On May 17-18, 2021, the Chicago Quantum Exchange (CQE) partnered with IBM Quantum and Super.tech to host the Pulselevel Quantum Control Workshop. At the workshop, representatives from academia, national labs, and industry addressed the importance of fine-tuning quantum processing at the physical layer. The purpose of this report is to summarize the topics of this meeting for the quantum community at large.

Optimizing QAOA on Bipotent Architectures

“…ECR-ZZ-SWAP OPT has the best performance, although the average CX gate error rate in ECR-circuits is 1.6 times higher than that in the Global-D. Optimizing both ZZ and ZZ-SWAP gates yields better and more stable AR and SP than optimizing only ZZ gates. Figure 14(b) shows the results of QAOA using ECRcircuits with qubits [16,14,11,8], Global-B with qubits [18,21,23,24], and Direct-circuit with qubits [1,4,7,6]. Despite having the highest fidelity, Global-B does not perform the best.…”

“…Figure 14(c) shows a performance comparison of 5Q-QAOA for PortOpt using ECR-circuits with qubits [16,14,11,8,9], Global-B with qubits [17,18,21,23,24] including two ECR-CX gates, and Direct-circuit with qubits [6,7,4,1,2]. While the Global-B and Directcircuit exhibit better fidelity and shorter schedule durations, ECR-ZZ-SWAP OPT outperforms them with the highest AR values.…”

“…We now investigate the performance of QAOA for MaxCut with 5 qubits. The qubits used in ECR-circuits, Global-B, and Direct-circuit are [16,14,11,8,9], [6, 7, 4, 1, 0], and [6,7,4,1,2], respectively. Figure 17 shows that Global-B, which has the highest fidelity, performs better for smaller p, whereas Direct-circuit, which has the lowest schedule duration, performs better for larger p. These results suggest that, when using default IBM gates, fidelity is more critical for medium-scale circuits, while a shorter schedule duration is more important for larger circuits.…”

“…have proven to be highly effective for regular quantum circuits, such as the Quantum Approximate Optimization Algorithm (QAOA) [5], where frequently occurring sub-circuits are mapped to efficient, bespoke sequences of pulses [3,6].…”