フルヤ　シュンスケ   FURUYA Shunsuke   古谷　峻介    所属   埼玉医科大学  医学部 教養教育    職種   専任講師
論文種別	学術雑誌(原著)
言語種別	英語
査読の有無	査読あり
表題	Polarization amplitude near quantum critical points
掲載誌名	正式名：PHYSICAL REVIEW B ISSNコード：2469-9950/2469-9969
出版社	AMER PHYSICAL SOC
巻・号・頁	99(14)
著者・共著者	Shunsuke C. Furuya,Masaaki Nakamura
発行年月	2019/04
概要	We discuss the polarization amplitude of quantum spin systems in one dimension. In particular, we closely investigate it in gapless phases of those systems based on the two-dimensional conformal field theory. The polarization amplitude is defined as the ground-state average of a twist operator which induces a large gauge transformation attaching the unit amount of the U(1) flux to the system. We show that the polarization amplitude under the periodic boundary condition is sensitive to perturbations around the fixed point of the renormalization-group flow rather than the fixed point itself even when the perturbation is irrelevant. This dependence is encoded into the scaling law with respect to the system size. In this paper, we show how and why the scaling law of the polarization amplitude encodes the information of the renormalization-group flow. In addition, we show that the polarization amplitude under the antiperiodic boundary condition is determined fully by the fixed point in contrast to that under the periodic one and that it visualizes clearly the nontriviality of spin systems in the sense of the Lieb-Schultz-Mattis theorem.
DOI	10.1103/PhysRevB.99.144426