New Universality Class in the S=1/2 Fibonacci Heisenberg Chains

TL;DR

This paper investigates the low energy behavior of S=1/2 Fibonacci Heisenberg chains, revealing a new universality class characterized by a logarithmically divergent dynamical exponent, distinct from known Fibonacci XY and XY chains.

Contribution

It introduces a novel universality class for Fibonacci Heisenberg chains, expanding understanding of aperiodic quantum spin chains.

Findings

Ground state belongs to a new universality class

Dynamical exponent diverges logarithmically

Distinct from Fibonacci XY and XY chains

Abstract

Low energy properties of the S=1/2 antiferromagnetic Heisenberg chains with Fibonacci exchange modulation are studied using the real space renormalization group method for strong exchange modulation. It is found that the ground state of this model belongs to a new universality class with logarithmically divergent dynamical exponent which is neither like Fibonacci XY chains nor like XY chains with relevant aperiodicity.