AI 中文总结
回顾半狄拉克费米子近期进展，其为二维准粒子，色散依运动方向而异，存在于拓扑里夫希茨转变处，介绍了在合成晶格和量子材料中的性质、证据，还从理论角度讨论了多体问题。
AI 中文摘要
本文回顾了半狄拉克费米子这一主题的近期进展。半狄拉克费米子是二维准粒子，其色散根据运动方向呈二次方（如伽利略不变粒子）或线性（如无质量相对论粒子）。这些粒子存在于由费米面连通性连续变化所设定的相边界，即拓扑里夫希茨转变处。文中介绍了它们在合成晶格和量子材料中的基本性质及当前存在的实验证据，并从理论角度讨论了与实验相关物理可观测量的多体问题。
英文摘要
This article reviews the recent progress on the subject of semi-Dirac fermions, two dimensional quasiparticles that disperse quadratically, as Galilean invariant particles, or linearly, as massless relativistic particles, depending on their direction of motion. These particles exist at a phase boundary set by the continuous change in the connectivity of Fermi surfaces, known as topological Lifshitz transitions. The basic properties and the current experimental evidence of the existence of these particles in both synthetic lattices and quantum materials are presented. The many-body problem of semi-Dirac fermions is discussed from a theoretical perspective with an eye to physical observables of relevance to experiments.
CommentsSubmitted to Reviews of Modern Physics
