[Paper Review] Quantum computing hardware for HEP algorithms and sensing

M. Sohaib Alam, S. Belomestnykh+38 more|arXiv (Cornell University)|Apr 19, 2022

Electronic and Structural Properties of Oxides24 citations

TL;DR

Reviews two promising superconducting quantum architectures for high-energy-physics (HEP) algorithms—3D cavity-based qudits (qutrits/qudits) and 2D cavity-based qudits—with discussions on encoding, scaling, interconnects, error protection, and potential HEP applications and sensing.

ABSTRACT

Quantum information science harnesses the principles of quantum mechanics to realize computational algorithms with complexities vastly intractable by current computer platforms. Typical applications range from quantum chemistry to optimization problems and also include simulations for high energy physics. The recent maturing of quantum hardware has triggered preliminary explorations by several institutions (including Fermilab) of quantum hardware capable of demonstrating quantum advantage in multiple domains, from quantum computing to communications, to sensing. The Superconducting Quantum Materials and Systems (SQMS) Center, led by Fermilab, is dedicated to providing breakthroughs in quantum computing and sensing, mediating quantum engineering and HEP based material science. The main goal of the Center is to deploy quantum systems with superior performance tailored to the algorithms used in high energy physics. In this Snowmass paper, we discuss the two most promising superconducting quantum architectures for HEP algorithms, i.e. three-level systems (qutrits) supported by transmon devices coupled to planar devices and multi-level systems (qudits with arbitrary N energy levels) supported by superconducting 3D cavities. For each architecture, we demonstrate exemplary HEP algorithms and identify the current challenges, ongoing work and future opportunities. Furthermore, we discuss the prospects and complexities of interconnecting the different architectures and individual computational nodes. Finally, we review several different strategies of error protection and correction and discuss their potential to improve the performance of the two architectures. This whitepaper seeks to reach out to the HEP community and drive progress in both HEP research and QIS hardware.

Motivation & Objective

• Motivate the development of quantum hardware tailored to HEP algorithms and sensing within the SQMS program.
• Assess two leading superconducting architectures (3D SRF cavities and 2D planar/qutrit implementations) for HEP applications.
• Identify encoding schemes, materials challenges, and error protection strategies to enable scalable HEP-relevant quantum computation.
• Discuss interconnectivity, transduction, room-temperature interfaces, and pathways to a community-accessible HEPCloud platform.

Proposed method

• Describe and evaluate 3D QPU architectures using SRF cavities coupled to non-linear ancillae for qudit encoding (Fock-basis, SNAP, ECD gates).
• Explain selective number-dependent arbitrary phase (SNAP) gates and displacement control for universal qudit operations in cavities.
• Present multi-mode and multi-cell SRF cavity concepts for scaling and mode interconnectivity.
• Outline 2D QPU implementations with qutrits and bosonic modes, including many-body simulations and material-loss considerations.
• Discuss inter-cavity coupling, tunable couplers, and quantum transduction approaches for networked quantum systems.
• Review error-protection and correction approaches (cat codes, binomial codes, driven-dissipative stabilization) and their applicability to qudit encodings.

Experimental results

Research questions

• RQ1 What are the viable superconducting hardware architectures (3D SRF cavity qudits vs. 2D QPU) for implementing HEP algorithms and sensing?
• RQ2 How can encoding schemes (Fock-basis, cat codes, binomial codes) and gate sets (SNAP, ECD) enable universal control in high-dimensional Hilbert spaces relevant to HEP?
• RQ3 What are the primary material, coherence, and scaling challenges for each architecture, and how can interconnectivity and transduction be realized?
• RQ4 What error-protection strategies are feasible for qudit-based architectures, and how do they impact algorithmic performance and resource requirements?
• RQ5 How can a dedicated HEPCloud platform provide standardized access to SQMS hardware for the HEP community?

Key findings

• 3D SRF cavity qudit architectures offer very long coherence times and large Hilbert spaces via Fock-state encoding and non-linear ancilla coupling.
• SNAP and displacement gate schemes enable universal control of cavity states, with optimal-control techniques substantially reducing gate times.
• Multi-mode and multi-cell cavities provide pathways to scale the Hilbert space, though inter-mode control and tunable couplers pose engineering challenges.
• 2D QPU implementations with qutrits and bosonic modes enable HEP-relevant simulations and many-body physics explorations, with material-loss considerations driving design choices.
• Error-protection approaches such as cat-bases, binomial codes, and driven-dissipative stabilization show promise for photon-loss protection, though active qudit error correction remains an open area.
• A HEPCloud framework is proposed to service the broader HEP community with standardized access to SQMS hardware and resources.