Type-II Topological Meissner States

TL;DR

This paper uncovers a new topological phase in a fermionic ladder model under high magnetic flux, featuring a circulating current and Majorana modes, revealing complex interplay between gauge fields and interactions.

Contribution

It introduces the type-II topological Meissner phase, distinguished from the type-I phase, characterized by high flux, circulating current, and Majorana end modes, using numerical methods.

Findings

Identification of the type-II topological Meissner phase

Presence of Majorana end modes in high flux regime

Interference effects between gauge fields and interactions

Abstract

We study the \emph{orbital effects} of the synthetic magnetic fields in an interacting square lattice two-leg fermionic ladder model with the number-conserving pair hopping that hosting the Majorana bound states. By utilizing density matrix renormalization group and exact diagonalization, we identify a novel type-II topological Meissner $($\emph{topo}-Meissner$)$ phase $($as distinguished from the low-field type-I \emph{topo}-Meissner state$)$ when threading a \emph{high} magnetic flux through the plaquette of the ladder, which not only exhibits a large uniformly circulating chiral current along the legs, the characteristics of the celebrated Meissner state, but also accommodates a topologically protected ground-state manifold due to the \emph{reentrant} emergence of the Majorana end modes. Our work reveals some interesting interference effects resulting from the interplay between the gauge fields and the strong interactions in establishing the intrinsic topological states of matter in low-dimensional quantum systems.