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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 |
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| 論文種別 | 学術雑誌(原著) |
| 言語種別 | 英語 |
| 査読の有無 | 査読なし |
| 表題 | Ground-State Phase Diagram of an Anisotropic S=1/2 Ladder with Different Leg Interactions |
| 掲載誌名 | 正式名：J. Phys. Soc. Jpn. 87, 104002 (2018) ISSNコード：0031-9015 |
| 出版社 | PHYSICAL SOC JAPAN |
| 巻・号・頁 | 87(10) |
| 著者・共著者 | Takashi Tonegawa,Toshiya Hikihara,Kiyomi Okamoto,Shunsuke C. Furuya,Tôru Sakai |
| 発行年月 | 2018/08/03 |
| 概要 | We explore the ground-state phase diagram of the $S=1/2$ two-leg ladder with<br /> different leg interactions. The $xy$ and $z$ components of the leg interactions<br /> between nearest-neighbor spins in the $a$ ($b$) leg are respectively denoted by<br /> $J_{ { \rm l},a}$ and $\Delta_{\rm l} J_{ { \rm l},a}$ ($J_{ { \rm l},b}$ and<br /> $\Delta_{\rm l} J_{ { \rm l},b}$). On the other hand, the $xy$ and $z$ components<br /> of the uniform rung interactions are respectively denoted by $\Gamma_{\rm r}<br /> J_{ { \rm r } }$ and $J_{ { \rm r } }$. In the above, $\Delta_{\rm l}$ and $\Gamma_{\rm<br /> r}$ are the $XXZ$-type anisotropy parameters for the leg and rung interactions,<br /> respectively. This system has a frustration when $J_{ { \rm l},a} J_{ { \rm<br /> l},b}<0$ irrespective of the sign of $J_{\rm r}$. The phase diagram on the<br /> $\Delta_{\rm l}$ ($|\Delta_{\rm l}| \leq 1.0$) versus $J_{ { \rm l},b}$<br /> ($-2.0\leq J_{ { \rm l},b}\leq 3.0$) plane in the case where $J_{ { \rm l},a}=0.2$,<br /> $J_{ { \rm r } }=-1.0$, and $\Gamma_{\rm r} = 0.5$ is determined numerically. We<br /> employ the physical consideration, and the level spectroscopy and<br /> phenomenological renormalization-group analyses of the numerical date obtained<br /> by the exact diagonalization method. The resultant phase diagram contains the<br /> ferromagnetic, Haldane, N{\'e}el, nematic Tomonaga-Luttinger liquid (TLL),<br /> partial ferrimagnetic, and $XY1$ phases. Interestingly enough, the nematic TLL<br /> phase appears in the strong-rung unfrustrated region as well as in the<br /> strong-rung frustrated one. We perform the first-order perturbational<br /> calculations from the strong rung coupling limit to elucidate the<br /> characteristic features of the phase diagram. Furthermore, we make the<br /> density-matrix renormalization-group calculations for some physical quantities<br /> such as the energy gaps, the local magnetization, and the spin correlation<br /> functions to supplement the reliability of the phase diagram. |
| DOI | 10.7566/JPSJ.87.104002 |
| arXiv ID | arXiv:1808.01090 |
| PermalinkURL | http://arxiv.org/abs/1808.01090v2 |