Department of Physics, Harvard University, Cambridge, MA 02138, USA.
J Phys Condens Matter. 2012 Jul 25;24(29):294205. doi: 10.1088/0953-8984/24/29/294205.
The critical theory of the onset of antiferromagnetism in metals, with concomitant Fermi surface reconstruction, has recently been shown to be strongly coupled in two spatial dimensions. The onset of unconventional superconductivity near this critical point is reviewed: it involves a subtle interplay between the breakdown of fermionic quasiparticle excitations on the Fermi surface and the strong pairing glue provided by the antiferromagnetic fluctuations. The net result is a logarithm-squared enhancement of the pairing vertex for generic Fermi surfaces, with a universal dimensionless coefficient independent of the strength of interactions, which is expected to lead to superconductivity at the scale of the Fermi energy. We also discuss the possibility that the antiferromagnetic critical point can be replaced by an intermediate 'fractionalized Fermi liquid' phase, in which there is Fermi surface reconstruction but no long-range antiferromagnetic order. We discuss the relevance of this phase to the underdoped cuprates and the heavy fermion materials.
金属中反铁磁有序的临界理论，伴随着费米面重构，最近在二维空间中被证明是强耦合的。本文综述了在这个临界点附近的非常规超导：它涉及到费米面的费米子准粒子激发的破坏和反铁磁涨落提供的强配对胶的微妙相互作用。最终结果是，对于一般的费米面，配对顶点的增强呈对数平方，其无量纲系数与相互作用的强度无关，预计这将导致费米能标上的超导。我们还讨论了反铁磁临界点是否可以被中间的“分数化费米液体”相取代的可能性，其中存在费米面重构但没有长程反铁磁序。我们讨论了这个相对于欠掺杂铜氧化物和重费米子材料的相关性。
