论文标题
通过破坏偶极系统中亚稳态的有效负特异性热
Effective negative specific heat by destabilization of metastable states in dipolar systems
论文作者
论文摘要
我们通过引入适当的数值方法来确定微磁温度并实现热浴的规范模型，从而在微型典型和规范集合中研究了偶性耦合的三维自旋系统。在微域合奏中，我们显示了低能区域中稳定的抗铁磁状态的分支。其他亚稳态的铁磁状态存在于该区域：通过外部扰动它们，获得了有效的负比热。在典型的合奏中，对于低温，相同的亚稳态状态是不稳定的，并达到了更坚固的亚稳态状态的新分支，这与稳定的状态不同。我们的统计物理方法使我们能够在偶极系统稳定和亚稳态状态的复杂结构中订购一些顺序。
We study dipolarly coupled three dimensional spin systems in both the microcanonical and the canonical ensembles by introducing appropriate numerical methods to determine the microcanonical temperature and by realizing a canonical model of heat bath. In the microcanonical ensemble, we show the existence of a branch of stable antiferromagnetic states in the low energy region. Other metastable ferromagnetic states exist in this region: by externally perturbing them, an effective negative specific heat is obtained. In the canonical ensemble, for low temperatures, the same metastable states are unstable and reach a new branch of more robust metastable states which is distinct from the stable one. Our statistical physics approach allows us to put some order in the complex structure of stable and metastable states of dipolar systems.
