Scan calculation of the density of states: Real-space cluster perturbation theory applied to the inhomogeneous Hubbard model in one dimension
Phys. Rev. B 112, 045146 – Published 28 July, 2025
DOI: https://doi.org/10.1103/q6vk-cjg8
Abstract
We present the spectral analysis of a one-dimensional Hubbard model with a parabolic potential, using a real-space cluster perturbation theory (CPT) designed to study spatially inhomogeneous electron systems with strong correlation. It is a natural extension of the conventional CPT to inhomogeneous cases by computing local Green's functions while averaging over multiple cluster boundaries. We find that the local density of states at each site mirrors that of a homogeneous system with the same local filling. This insight provides a perspective on spectral evolution in inhomogeneous systems used to scan the occupancy-dependent features of the homogeneous system, making this setup a practical one-shot spectroscopy tool for ultracold atoms in harmonic traps.
