Spectral gaps of 2D and 3D quantum many-body systems in thermodynamic limit

We present an expression for the energy gap between the ground and the first exited state of quantum many-body systems, opening up new prospects for performing and accelerating spectral calculations. We develop and demonstrate one such possibility in the context of tensor network simulations. Our approach requires only minor modifications of the widely used Simple Update method and is computationally lightweight relative to other approaches [1].

The work is supported by the National Research Foundation of Ukraine under the call “Excellent science in Ukraine”, grant No. 0124U004372.

References:

[1] I. V. Lukin, A. G. Sotnikov, J. M. Leamer, A. B. Magann, D. I. Bondar, Spectral Gaps of 2D and 3D Many-body Quantum Systems in the Thermodynamic Limit, Phys. Rev. Research 6, 023128 (2024), https://doi.org/10.1103/PhysRevResearch.6.023128