论文标题
磁场下的两通道围质晶格模型中的通道选择性非FERMI液体行为
Channel-selective non-Fermi liquid behavior in the two-channel Kondo lattice model under a magnetic field
论文作者
论文摘要
通过在应用磁场中的非kramers $ f $ - 电子系统中发现的异常行为刺激，我们通过使用持续的均值均值理论的簇扩展与连续的量子量蒙特卡洛法相结合，研究了两通道近孔晶状体模型。我们以两种方式包括外部磁场的效果：Zeeman耦合到传导电子旋转，并通过晶体电场分开通过晶状体自由度与四极自由度的有效耦合。我们表明，磁场抑制了抗心肌自旋顺序（物理上，对应于抗癌 - 质子序列），并产生一种通道选择性的非fermi液态状态，其中两个通道之一（物理上，旋转或-down）之一（物理上，旋转或 - down）表现出非液体行为，而其他液体表现出液体液体行为，而在fimi液体中则表现出较高的液态。这种异常状态出现在圆顶形的区域，该区域从抗毒素旋转有序相位到顺磁性相延伸。我们发现，在这个圆顶形的区域中，增强了复合相关性的量度，这是两个通道之间的临界耦合分化的量度。我们还发现，在顺磁侧的该区域中，特定的热系数增强了，这表明较重的费米昂行为不仅在临界场附近的抗毒素旋转顺序在该附近消失，而且在该田间和温度的某个区域中也消失了。我们讨论了与普通的Kondo晶格模型相比的结果。我们还讨论了我们的发现对1-2-20种化合物中观察到的特殊行为的影响，例如$ \ rm {prir_2zn_ {20}} $，$ \ rm {prrh_2zn_ {20}}} $，以及$ \ rm \ rm {prv_2al_ {20} $
Stimulated by anomalous behaviors found in non-Kramers $f$-electron systems in an applied magnetic field, we study a two-channel Kondo lattice model by using a cluster extension of the dynamical mean-field theory combined with the continuous-time quantum Monte Carlo method. We include the effect of the external magnetic field in two ways: the Zeeman coupling to conduction electron spins and an effective coupling to the quadrupole degree of freedom through the crystalline electric field splitting. We show that the magnetic field suppresses the antiferroic-spin order (physically, corresponding to the antiferroic-quadrupole order), and yields a channel-selective non-Fermi liquid state where one of the two channels (physically, spin-up or -down) exhibits non-Fermi liquid behavior while the other shows Fermi liquid behavior, before entering the Fermi liquid regime in higher fields. This anomalous state appears in a dome-shaped region which extends from inside the antiferroic-spin ordered phase to the paramagnetic phase. We find that the composite correlation, which is a measure of differentiation in the Kondo coupling between the two channels, is enhanced in this dome-shaped region. We also find that the specific heat coefficient is enhanced in this region in the paramagnetic side, indicating heavy fermion behavior not only in the vicinity of the critical field where the antiferroic-spin order vanishes but also in a certain region of the field and temperature. We discuss the results in comparison with the ordinary Kondo lattice model. We also discuss the implication of our findings to the peculiar behavior observed in the 1-2-20 compounds such as $\rm{PrIr_2Zn_{20}}$, $\rm{PrRh_2Zn_{20}}$, and $\rm{PrV_2Al_{20}}$ under a magnetic field.
