Electron pairing in one-dimensional quasicrystals

TL;DR

This study investigates how electron pairing in one-dimensional binary Hubbard chains is affected by periodic and quasiperiodic modulations, revealing a critical band-filling where behaviors invert, using advanced numerical methods.

Contribution

It introduces a detailed analysis of electron pairing in quasiperiodic systems, highlighting the impact of Fibonacci sequence modulation on pairing behavior and phase diagrams.

Findings

Identification of a critical band-filling where behaviors reverse

Comparison of periodic and Fibonacci modulated chains

Phase diagram of electron pairing states

Abstract

Electron pairing in one-dimensional binary Hubbard chains is studied for different values of the band-filling using the Density Matrix Renormalization Group method. The systems consist of linear arrays of sites with two types of on-site correlations defined by two potentials: U_A being attractive (< 0), and U_B repulsive (> 0). The atomic levels of the system are modulated with periodic and quasiperiodic ordering, in the latter case following the Fibonacci sequence. We analyze the effect of such modulations and calculate the electron pairing phase diagram as a function of the band-filling. It is observed that there is a critical value of the band-filling where the behavior of the periodic and the Fibonacci binary Hubbard chains is reversed.