Ising Meson Spectroscopy Simulation Achieves Improved Resolution on Quantum Device Via Error-Resilient Techniques

The challenge of simulating complex quantum systems, such as those described by the transverse-field Ising model, currently limits our ability to verify fundamental predictions about confinement and excitation spectra. Hao-Ti Hung from National Taiwan University, Isabel Nha Minh Le and Johannes Knolle from Technical University of Munich, along with Ying-Jer Kao from National Taiwan University, now demonstrate a significant advance in this field. The team successfully performs improved spectroscopy of confined excitations using a noisy quantum device, employing two distinct error-resilient circuit construction techniques. By analysing time-series data with error mitigation, they identify key signatures of symmetry, validating the potential of both circuit compression and hardware-efficient compilation for exploring complex topological phenomena on near-term quantum computers.

Quantum Physics, Condensed Matter, and Computing Research

This document presents research focused on quantum physics, condensed matter physics, and quantum computing. It details investigations into the behavior of quantum systems, ranging from theoretical developments in understanding interacting quantum particles to practical implementations using technologies like Rydberg atoms and superconducting qubits. The research explores both fundamental properties of materials and the development of algorithms for future quantum computers. Key areas of investigation include quantum many-body physics, which examines the collective behavior of numerous interacting quantum particles, and the development of quantum algorithms designed to solve complex problems beyond the reach of classical computers. Researchers also explore condensed matter physics, focusing on the quantum properties of materials, and utilize diverse platforms for quantum simulation, including Rydberg atoms, trapped ions, and superconducting qubits. Numerical methods play a crucial role in solving complex quantum problems and validating theoretical predictions.

Ising Model Simulation via Quantum Circuits

Scientists investigated the behavior of the transverse-field Ising model, a system crucial for understanding fundamental physics, by performing quantum simulations on a quantum processor. To accurately determine the system’s properties, the team focused on extracting the energy spectrum of its excitations, a challenging task requiring complex quantum circuits. Researchers developed two distinct methods for constructing the time-evolution operator, a core component of the simulation, to overcome limitations imposed by hardware noise and circuit complexity. The first approach directly constructed the operator using the processor’s native gates, minimizing errors.

Complementing this, the team developed a technique employing Riemannian optimization, which compresses the circuit by approximating the evolution operator with a simpler, fixed-depth circuit. This effectively reduces the circuit’s complexity while preserving accuracy, a critical step for simulations on current quantum devices. To further refine the results, scientists implemented an error mitigation strategy to correct for signal decay, enhancing the reliability of the extracted data. The study prepared a specific initial state and then measured the dynamical structure factor, a key quantity for determining excitation energies. Instead of directly calculating this quantity, the team innovatively focused on the magnetization at the center of the system, demonstrating that its dynamics in the frequency domain provide sufficient information to extract the desired spectrum. To validate their approach, scientists performed classical simulations and compared the results with theoretical predictions, confirming the viability of their methodology.

E8 Mass Spectrum Simulated on Quantum Hardware

Scientists probed the behavior of confined excitations within the transverse-field Ising model, a system exhibiting unique symmetry near critical points, using quantum simulations. The research team achieved improved measurements of these excitations by employing two error-resilient circuit construction techniques: direct construction using native gates and circuit compression via Riemannian optimization. By analyzing the frequency spectrum of error-mitigated data, the team identified signatures of E8 symmetry, despite the inherent noise present in quantum hardware. The study focused on simulating the dynamics of specific initial states and then extracting the central-site magnetization, analyzing its frequency spectrum to identify characteristic energy levels predicted by E8 quantum field theory.

Simulations, validated by comparison with classical computer results, demonstrated the ability to accurately determine the excitation spectrum. This work confirms the effectiveness of both circuit compression and hardware-efficient compilation for probing complex phenomena on near-term quantum devices. The results demonstrate that the observed energy levels align with theoretical predictions, validating the framework and providing evidence for the emergence of E8 symmetry within the simulated system. This breakthrough establishes a pathway for exploring complex quantum systems and verifying theoretical predictions using increasingly sophisticated quantum hardware.