ABSTRACT

We investigate the magnetisation and internal energy of the David star in the Kagome lattice by the effective field theory developed by Kaneyoshi. First-order, Second-order and successive phase transitions are observed for different spin-down orientations. Spin-down orientation of identical atoms causes a second-order phase transition, spin-down orientation of different atoms causes a first-order and successive phase transitions. Minimum internal energy is obtained as U_{David star}=−5 for all spin-up orientations, whereas it increases (U_{David star}> −5) for at least one spin-down orientation. For spin-down orientation of A↑–A↓, internal energy becomes zero at a certain temperature and we call this temperature ‘zero internal energy temperature (Tzie)’. At T < Tzie=1.99, internal energy is positive, whereas it is negative for other spin states. Therefore, spin-induced minimum internal energy broken is observed except for all spin-up (A↑, B↑ and C↑) cases.

摘要

我们根据Kaoshioshi开发的有效场论研究了Kagome晶格中David恒星的磁化和内部能量。对于不同的向下旋转方向，观察到一阶，二阶和连续相变。相同原子的自旋向下取向导致二阶相变，不同原子的自旋向下取向引起一阶及连续相变。对于所有向上旋转方向，当U _{David star} = -5时，获得最小内部能量，而内部能量增加（U _{David star}> -5）至少有一个向下旋转方向。对于A↑–A↓的向下旋转方向，在一定温度下内部能量变为零，我们将此温度称为“零内部能量温度（Tzie）”。当T  <Tzie = 1.99时，内部能量为正，而其他自旋态则为负。因此，除了所有自旋（A↑，B↑和C↑）情况，都观察到了自旋引起的最小内能断裂。