Carlos Ortiz Marrero

Nonlocal Games as Cross-Platform Quantum Benchmarks: Exceeding unconditional classical bounds on trapped-ion processors

Anton T. Than [1,5], Jim Furches [2], Debopriyo Biswas [3], Sarah Chehade [4,7], Kathleen Hamilton [4], Bahaa Harraz [3], Xingxin Liu [1,5], De Luo [3], Keqin Yan [3], Yichao Yu [3], Vivian Ni Zhang [3], Liudmila A. Zhukas [3], Alaina M. Green [1,5], Alexander Kozhanov [3], Christopher Monroe [3], Crystal Noel [3], Carlos Ortiz Marrero [2,6], Norbert M. Linke [1,3,5]

Abstract

Nonlocal games provide application-level benchmarks for quantum hardware whose classical performance bounds are information-theoretic, holding against all classical strategies regardless of computational resources. We implement a 14-vertex graph coloring game, the smallest graph exhibiting a quantum-classical separation for this game type, on four trapped-ion quantum processors across three institutions. One system achieved a win rate that surpasses the classical bound with statistical significance, marking the first violation of a classical bound in a graph coloring nonlocal game on quantum hardware. The remaining systems achieved win rates comparable to the best superconducting processors evaluated on the same game, further illustrating the potential of nonlocal games as cross-architecture quantum benchmarks.

Hybridlane: A Software Development Kit for Hybrid Continuous-Discrete Variable Quantum Computing

Jim Furches [1], Timothy J. Stavenger [1], Carlos Ortiz Marrero [1,2]

Abstract

Hybrid quantum computing systems that combine discrete-variable qubits with continuous-variable qumodes offer promising advantages for quantum simulation, error correction, and sensing applications. However, existing quantum software frameworks lack native support for expressing and manipulating hybrid circuits, forcing developers to work with fragmented toolchains or rely on simulation-coupled representations that limit scalability. We present Hybridlane, an open-source software development kit providing a unified frontend for hybrid continuous-discrete variable quantum computing. Hybridlane introduces automatic wire type inference to distinguish qubits from qumodes without manual annotations, enabling compile-time validation of circuit correctness. By decoupling gate semantics from matrix representations, Hybridlane can describe wide and deep circuits with minimal memory consumption and without requiring simulation. The framework implements a comprehensive library of hybrid gates and decompositions following established instruction set architectures, while remaining compatible with PennyLane's extensive qubit algorithm library. Furthermore, it supports multiple backends including classical simulation with Bosonic Qiskit and hardware compilation to Sandia National Laboratories' QSCOUT ion trap. We demonstrate Hybridlane's capabilities through bosonic quantum phase estimation and ion trap calibration workflows.