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	Dimensional modulation of spontaneous magnetic order in quasi-two-dimensional quantum antiferromagnets
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	94(14)
著者・共著者	Shunsuke C. Furuya,Maxime Dupont,Sylvain Capponi,Nicolas Laflorencie,Thierry Giamarchi
発行年月	2016/10
概要	Spontaneous symmetry breaking is deeply related to the dimensionality of a system. The Neel order going with spontaneous breaking of U(1) symmetry is safely allowed at any temperature for three-dimensional systems but allowed only at zero temperature for purely two-dimensional systems. We closely investigate how smoothly the ordering process of the three-dimensional system is modulated into that of the two-dimensional one with reduction of dimensionality, considering spatially anisotropic quantum antiferromagnets. We first show that the Neel temperature is kept finite even in the two-dimensional limit although the Neel order is greatly suppressed for low dimensionality. This feature of the Neel temperature is highly nontrivial, which dictates how the order parameter is squashed under the reduction of dimensionality. Next, we investigate this dimensional modulation of the order parameter. We develop our argument taking as an example a coupled spin-ladder system relevant for experimental studies. The ordering process is investigated multidirectionally using theoretical techniques of a mean-field method combined with analytical (exact solutions of quantum field theories) or numerical (density-matrix renormalization-group) methods, a variational method, a renormalization-group study, linear spin-wave theory, and quantum Monte Carlo simulations. We show that these methods independent of each other lead to the same conclusion about the dimensional modulation.
DOI	10.1103/PhysRevB.94.144403
arXiv ID	arXiv:1607.05381
PermalinkURL	http://arxiv.org/abs/1607.05381v2