2023/12/10 by Parameshwar R. Pasnoori, Pasnoori, Parameshwar R., Yicheng Tang +9 · 2 citations
Mathematics · Physics and Astronomy · #Algebraic structures and combinatorial models #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum Physics (quant-ph) #Quantum many-body systems #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2312.05970
openalex publication_date 2023/12/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this work we argue that the antiferromagnetic spin (1)/(2) XXZ chain in the gapped phase with boundary magnetic fields hosts fractional spin (1)/(4) at its edges. Using a combination of Bethe ansatz and the density matrix renormalization group we show that these fractional spins are sharp quantum observables in both the ground and the first excited state as the associated fractional spin operators have zero variance. In the limit of zero edge fields, we argue that these fractional spin operators once projected onto the low energy subspace spanned by the ground state and the first excited state, identify with the strong zero energy mode discovered by P. Fendley \citeFendley.