摘要
One challenge in contemporary condensed matter physics is to understand unconventional electronic physics beyond the paradigm of Landau Fermi-liquid theory. Here, we present a perspective that posits that most such examples of unconventional electronic physics stem from restrictions on the degrees of freedom of quantum electrons in Landau Fermi liquids. Since the degrees of freedom are deeply connected to the system＇s symmetries and topology, these restrictions can thus be realized by external constraints or by interaction-driven processes via the following mechanisms： （i） symmetry breaking, （ii） new emergent symmetries, and （iii） nontrivial topology. Various examples of unconventionM elec- tronic physics beyond the reach of traditional Landau Fermi liquid theory are extensively investigated from this point of view. Our perspective yields basic pathways to study the breakdown of Landau Fermi liquids and also provides a guiding principle in the search for novel electronic systems and devices.
One challenge in contemporary condensed matter physics is to understand unconventional electronic physics beyond the paradigm of Landau Fermi-liquid theory. Here, we present a perspective that posits that most such examples of unconventional electronic physics stem from restrictions on the degrees of freedom of quantum electrons in Landau Fermi liquids. Since the degrees of freedom are deeply connected to the system＇s symmetries and topology, these restrictions can thus be realized by external constraints or by interaction-driven processes via the following mechanisms： （i） symmetry breaking, （ii） new emergent symmetries, and （iii） nontrivial topology. Various examples of unconventionM elec- tronic physics beyond the reach of traditional Landau Fermi liquid theory are extensively investigated from this point of view. Our perspective yields basic pathways to study the breakdown of Landau Fermi liquids and also provides a guiding principle in the search for novel electronic systems and devices.
基金
We thank Tao Li and Yin Zhong for help- ful discussions. H. T. Lu acknowledges the support of the National Natural Science Foundation of China （Grant No. 11474136）. Y. H. Su was partially supported by the Natural Science Foundation of China （Grant No. 11774299） and the Natural Science Foundation of Shandong Province （Grant No. ZR2017MA033）.
