Extended Aharonov-Bohm period analysis of strongly correlated electron systems

TL;DR

This study numerically investigates the extended Aharonov-Bohm period in strongly correlated electron systems, revealing boundary-induced period halving and its relation to pairing and phase transitions, with implications for low-energy physics and integrability.

Contribution

It provides the first detailed numerical analysis of the extended AB period in strongly correlated systems, linking period changes to phase transitions and pairing phenomena.

Findings

Boundary-induced halving of the AB period observed

Extended AB period relates to pairing and phase separation

Period remains unchanged across integrable and nonintegrable boundaries

Abstract

The `extended Aharonov-Bohm (AB) period' recently proposed by Kusakabe and Aoki [J. Phys. Soc. Jpn (65), 2772 (1996)] is extensively studied numerically for finite size systems of strongly correlated electrons. While the extended AB period is the system length times the flux quantum for noninteracting systems, we have found the existence of the boundary across which the period is halved or another boundary into an even shorter period on the phase diagram for these models. If we compare this result with the phase diagram predicted from the Tomonaga-Luttinger theory, devised for low-energy physics, the halved period (or shorter periods) has a one-to-one correspondence to the existence of the pairing (phase separation or metal-insulator transition) in these models. We have also found for the t-J model that the extended AB period does not change across the integrable-nonintegrable boundary despite the totally different level statistics.