Year: 2025
Type: article
Abstract: To understand the dynamics of quantum many-body systems, it is essential to study excited eigenstates. While tensor network states have become a standard tool for computing ground states in computational many-body physics, obtaining accurate excited eigenstates remains a significant challenge. In this work, we develop an approach that combines the inexact Lanczos method, which is designed for efficient computations of excited states, with tree tensor network states (TTNSs). We demonstrate our approach by computing excited vibrational states for three challenging problems: (1) 122 states in two different energy intervals of acetonitrile (12-dimensional), (2) Fermi resonance states of the fluxional Zundel ion (15-dimensional), and (3) selected excited states of the fluxional and very correlated Eigen ion (33-dimensional). The proposed TTNS inexact Lanczos method is directly applicable to other quantum many-body systems.
Source: The Journal of Chemical Physics
DOI: 10.1063/5.0301263
Authors: Madhumita Rano, Henrik R. Larsson
Institution: University of California, Merced
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: National Science Foundation
Awards: CC* Regional Computing: CENVAL-ARC: Central Valley Accessible Research and Computational Hub, State-Resolved Vibrational Spectra of Fluxional Protonated Water Clusters via Tensor Network States, MRI: Acquisition of Pinnacles -- Raising Research Computing to New Heights in California's Central Valley
OpenAlex ID: W4415424871