Generic susceptibilities of the half-filled Hubbard model in infinite dimensions

TL;DR

This paper investigates the charge, spin, and Cooper-pair susceptibilities of the half-filled Hubbard model in infinite dimensions, revealing key differences in excitation behaviors across the metal-insulator transition.

Contribution

It provides high-resolution results for susceptibilities in both metallic and insulating phases using dynamic density-matrix renormalization, highlighting the evolution of magnetic moments and low-energy spin peaks.

Findings

Saturated local magnetic moments in the insulating phase

Pronounced low-energy spin response in the metallic phase

Distinct susceptibility behaviors across the Mott transition

Abstract

Around a metal-to-insulator transition driven by repulsive interaction (Mott transition) the single particle excitations and the collective excitations are equally important. Here we present results for the generic susceptibilities at zero temperature in the half-filled Hubbard model in infinite dimensions. Profiting from the high resolution of dynamic density-matrix renormalization at all energies, results for the charge, spin and Cooper-pair susceptibilities in the metallic and the insulating phase are computed. In the insulating phase, an almost saturated local magnetic moment appears. In the metallic phase a pronounced low-energy peak is found in the spin response.