Benchmarking Quantum Computers via Protocols -- Comparing Superconducting and Ion-Trap Quantum Technology

Abstract

Superconducting and Ion-Trap quantum architectures are common in the current landscape of the quantum computing field, each with distinct characteristics and operational constraints. Understanding and measuring the underlying quantumness of these devices is essential for assessing their readiness for practical applications and guiding future progress and research. Building on earlier work (Meirom, Mor, Weinstein Arxiv 2505.12441), we utilize a benchmarking strategy applicable for comparing these two architectures by measuring "quantumness" directly on optimal sub-chips. Distinct from existing metrics, our approach employs rigorous binary fidelity thresholds derived from the classical limits of state transfer. This enable us to definitively establish quantum advantage of a designated sub-region. We apply this quality assurance methodology to industry leading platforms from both technologies. This comparison provides a protocol-based evaluation of quantumness advantage, revealing not only the strengths and weaknesses of each tested chip and its sub-chips but also offering a common language for their assessment. By abstracting away technical differences in the final result, we demonstrate a benchmarking strategy that bridges the gap between disparate quantum-circuit technologies, enabling fair performance comparisons and establishing a critical foundation for evaluating future claims of quantum advantage.

Figures (31)

• Figure 1: The protocols used in this work, we adjusted them in order be compatible with AQT's all-to-all connectivity. The generalized transmit and generalized do-nothing protocols are presented with $M=2$. On AQT's quantum computer the swap distance between 2 qubits is always 1, while in IBM's hardware the swap distance depends on the path we choose
• Figure 2: IBM's Heron-r2 series qubits connectivity map. Each rectangle is assigned with a number for consistent reference
• Figure 3: The optimal lookup workflows for AQT (left) and IBM (right)
• Figure 4: A detailed view of the qubit connectivity map for the IBM Heron-r2 architecture, illustrating the physical layout and grouping of the numbered rectangular sub-chips (e.g., 1, 2, and 5).
• Figure 5: Connectivity topology of the AQT IBEX Q1 processor. (a) The effective logical connectivity, illustrated as a complete graph. The system supports all-to-all connectivity, allowing the execution of arbitrary two-qubit gates between any pair of the 12 ions without intermediate SWAP operations. (b) We speculate that the physical interaction mechanism is actually a star topology as originally suggested by Cirac and Zoller PhysRevLett.74.4091. Connectivity is mediated by a centralized, shared phonon mode (P). While this common bus facilitates the all-to-all coupling seen in (a), it necessitates making the entangling operations in a series instead of in parallel. The central phonon mode acts solely as a mediator and is not part of the computational qubits set. Note that this graph is only an illustration. Physically the ions lay in line and not in a circle