国立研究開発法人量子科学技術研究開発機構(QST) / 量子ビーム科学部門 / 関西光科学研究所 / 放射光科学研究センター / 量子シミュレーション研究グループ
Japanese | English (Top page)
日時: | 平成23年12月13日(火) 16:00〜 |
Date and time: | 13th Dec. (Tue.) 16:00〜 |
場所: | SPring-8, 萌光館 |
Place: | SPring-8, "HOUKOUKAN" seminar room |
Title: | Multiple-Q states and skyrmion lattice of the triangular-lattice Heisenberg antiferromagnet under magnetic fields |
講演者: | 大久保 毅 氏(大阪大学・理学研究科・宇宙地球) |
Speaker: | Dr. Tsuyoshi Okubo (Osaka University) |
Abstract: |
We study the ordering of the classical antiferromagnetic Heisenberg model on the triangular lattice with the next-nearest-neighbor (or the third-neighbor) interaction under magnetic fields by means of a mean-field analysis and a Monte Carlo simulation. When further-neighbor interactions become dominant, the ground state in zero magnetic field takes an incommensurate helical spin structure, which has three-fold degeneracy associated with three equivalent directions of the wavevector on the triangular lattice. We show that not only a simple single-Q state but also a variety of multiple-Q states, including the so-called "skyrmion-lattice" state, are stabilized under applied magnetic fields.