| 題目 | Finitely correlated S=1/2 chains with orbital degeneracy |
| 講師 | Prof. H. -J. Mikeska
（Hannover University (理研)） |
| 日時 | 10 月 10 日（火）15:00 - 16:30 |
| 場所 | コラボレーションセンター３階 コラボレーション室
（岡山大学津島キャンパス内） |
| 要旨 | We have investigated the phase diagram and elementary excitations of a S=1/2 chain of ions with an additional orbital degree of freedom. We report results on the gapful phase of this system, including the effects of orbital anisotropy, where the system is dimerized as demonstrated by giving exact ground states for special values of the exchange constants. Elementary excitations will be shown to exist as solitons and magnons; they involve both orbital and spin degrees of freedom and are treated both numerically and in a variational approach. An extension to a t-J like model in the presence of impurities will also be discussed. |
| 世話人 | 物理学科 原田勲 (TEL: 086-251-7808） |
