Ferromagnetic clouds caused by hole motion in a one-dimensional $t$-$J$ mode

TL;DR

This paper investigates the formation of ferromagnetic clouds, large magnetic polarons, caused by hole motion in a one-dimensional $t$-$J$ model, revealing partial ferromagnetic phases with bound states around the hole.

Contribution

It introduces the concept of ferromagnetic clouds as bound states in a 1D $t$-$J$ model, linking them to Nagaoka ferromagnetism and partial ferromagnetic phases.

Findings

Identification of ferromagnetic clouds as bound states around holes.

Partial ferromagnetic phases appear in the phase diagram.

Ferromagnetic clouds behave as heavy magnetic polarons.

Abstract

The one-dimensional $t_1$-$t_2$-$J_1$-$J_2$ model is examined in the one-hole case, in which the total number of electrons is one less than the number of the lattice sites. The ground-state phase diagram includes a series of partial ferromagnetic phases, which are stacked in a regime of positive and small $J_1$. We find that the ground state in each of these partial ferromagnetic phases includes a ferromagnetic cloud, which is a multiple-spin bound state together with the hole. The ferromagnetic cloud is a large magnetic polaron with a heavy mass in a single-band electronic system and is supposedly formed as a result of Nagaoka ferromagnetism which locally works around the hole.