セミナー情報

原子力機構・兵県大合同物性コロキウム(第65回)

日時: 平成22年2月9日(火) 16:30〜
Date and time: 9th February (Tue.) 16:30〜
場所: SPring-8, 萌光館
Place: SPring-8, "HOUKOUKAN" seminar room
題名: 整合ー非整合転移の理論
Title: Theory of commensurate-incommensurate transition
講演者: 野村清英  氏 (九州大理学部物理)
Speaker: Prof. Kiyhide Nomura (Dept. of Physics, Kyushu University)
Abstract:

整合ー非整合(C-IC)転移は、量子 S=1 bilinear-biquadratic鎖、朝永ラッテンジャー流体と高温の常磁性領域とのクロスオーバー、古典 ANNNI モデル、三角格子のスピン系など多くの場合に見られる。 我々は複素平面の特異点を考察し、非整合が起きるメカニズムを提案した[1,2]。 量子系だけでなく、古典系についても議論する。

Phenomena of the commensurate-incommensurate (C-IC) transitions are observed in many cases, such as in the quantum S=1 bilinear-biquadratic chain, the crossover between the Tomonaga-Luttinger-liquid and the high-temperature paramagnetic region, classical ANNNI models. We have proposed a mechanism to explain the onset of the incommensurability [1], considering singularity in the complex plane. We also talk the C-IC change of the classical NNNI spin chain, the simplest case of ANNNI spin models. We find that the asymmetry of the transfer matrix is related with the C-IC change.

[1] K. Nomura, J. Phys. Soc. Jpn., Vol.72, (2003) 476.
[2] T. Murashima and K. Nomura, Phys. Rev. B 73, (2006) 214431.