Large- N approach to the two-channel Kondo lattice
Large- N approach to the two-channel Kondo lattice
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DOI：
10.1103/physrevb.101.075133
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发表时间：
2019-11
影响因子：
3.7
通讯作者：
Ari Wugalter;Y. Komijani;P. Coleman
中科院分区：
文献类型：
--
作者：
Ari Wugalter;Y. Komijani;P. Coleman
本文研究了半填充大n极限下的双通道Kondo晶格。在这个模型中，连续的通道对称性被自发地打破，形成一个通道铁磁，其中一个传导通道形成近藤绝缘体，而另一个保持导电。本文讨论了如何用“序分化”的概念来理解这种基态，其中通道磁化分解为一个涌现的旋量序参数。通过积分出费米子，我们得到了描述这种对称性破缺及其涌现的集体模式的有效作用。一个值得注意的观察是，有序参数的拓扑缺陷携带U(1)通量，表现为围绕缺陷运行的电子拾取的Aharonov-Bohm相位。通过对有效作用的研究，我们认为相图中包含了大费米表面和小费米表面之间的非磁跃迁。
This paper studies the two-channel Kondo lattice in the large-N limit at half-filling. In this model, the continuous channel-symmetry is spontaneously broken, forming a channel ferromagnet in which one conduction channel forms a Kondo insulator, while the other remains conducting. The paper discusses how this ground-state can be understood using the concept of "order fractionalization", in which the channel magnetization breaks up into an emergent spinor order parameter. By integrating out the fermions we derive an effective action that describes this symmetry breaking and its emergent collective modes. A remarkable observation is that topological defects in the order parameter carry a U(1) flux, manifested in the Aharonov-Bohm phase picked by electrons that orbit the defect. By studying the effective action, we argue that the phase diagram contains a non-magnetic transition between a large and a small Fermi surface.