Quantum Magnetism from Low-Dimensional Quantum Ising Models with Quantum Integrability

Abstract Quantum integrability provides a unique and powerful framework for accurately understanding quantum magnetism. In this review, we focus specifically on several quantum integrable low-dimensional quantum Ising models. We begin with the transverse field Ising chain (TFIC) at quantum critical point and examine how it evolves under perturbations, such as an applied longitudinal field or weak coupling to another quantum critical TFIC. These perturbations reveal a wealth of emergent quantum integrable field theories with exotic many-body excitations, elegantly characterized by conformal invariance and the E 8 and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>D</mml:mi> <mml:mn>8</mml:mn> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:msubsup> </mml:mrow> </mml:math> Lie algebras, respectively. In exploring these models, we also delve into the framework of exact scattering matrices, which is related to determining spin dynamics within these systems. Finally, we show how the emergent phenomena in these integrable quantum Ising models find experimental realization in Co-based quasi-one-dimensional quantum magnetic materials. The substantial theoretical and experimental advancements in these systems highlight the profound connections between quantum integrable field theory, statistical field theory, and condensed matter physics.