Surface Magnetization of Aperiodic Ising Quantum Chains

TL;DR

This paper investigates the surface magnetization in aperiodic Ising quantum chains, revealing that the critical exponent remains universal while the amplitude varies with sequence modulation and initial conditions.

Contribution

It provides exact results for surface magnetization in aperiodic quantum chains, including quasiperiodic and Thue-Morse sequences, highlighting universality of the critical exponent.

Findings

Surface magnetization exponent is always 1/2 across studied sequences.

Critical amplitude depends on modulation strength and initial chain position.

Exact fermion-based calculations confirm universality of the critical exponent.

Abstract

We study the surface magnetization of aperiodic Ising quantum chains. Using fermion techniques, exact results are obtained in the critical region for quasiperiodic sequences generated through an irrational number as well as for the automatic binary Thue-Morse sequence and its generalizations modulo p. The surface magnetization exponent keeps its Ising value, beta_s=1/2, for all the sequences studied. The critical amplitude of the surface magnetization depends on the strength of the modulation and also on the starting point of the chain along the aperiodic sequence.