Resonating dimer-monomer liquid state in a magnetization plateau of a spin-$\frac{1}{2}$ kagome-strip Heisenberg chain

TL;DR

This paper investigates a highly frustrated spin-1/2 kagome-strip chain, revealing a novel gapless spin liquid state in a magnetization plateau, characterized by entanglement properties and proposing a resonating dimer-monomer liquid state.

Contribution

It introduces a new gapless spin liquid state in a kagome-strip chain and characterizes its entanglement and dynamic properties using DMRG methods.

Findings

Discovery of a gapless spin liquid state at 1/5 magnetization plateau

Identification of doubly degenerate entanglement spectra

Observation of a gapless continuum in dynamic spin structure

Abstract

Highly frustrated spin systems such as the kagome lattice (KL) are a treasure trove of new quantum states with large entanglements. We thus study the spin-$\frac{1}{2}$ Heisenberg model on a kagome-strip chain (KSC), which is one-dimensional KL, using the density-matrix renormalization group (DMRG) method. Calculating central charge and entanglement spectrum for the KSC, we find a novel gapless spin liquid state with doubly degenerate entanglement spectra in a 1/5 magnetization plateau. We also obtain a gapless low-lying continuum in the dynamic spin structure calculated by dynamical DMRG method. We propose a resonating dimer-monomer liquid state that would meet these features.