标题： 在三层石墨烯中控制分数量子霍尔态的粒子-空穴对称性 显示英文标题

标题： Controlling particle-hole symmetry of fractional quantum hall states in trilayer graphene

摘要： 我们对多带系统中关于半填充的分数量子霍尔（FQH）态的粒子-空穴对称性（PHS）进行了详细的实验研究。 具体而言，我们关注Bernal堆叠的三层石墨烯（TLG）中类似单层的能带的最低朗道能级。 在原始TLG中，奇分母FQH态的激发能隙、朗德g因子、有效质量和无序展宽与其空穴共轭态相同。 这种精确的PH对称性源于晶格镜像对称性，该对称性阻止了朗道能级之间的混合。 引入非零的位移场\(D\)会破坏这种镜像对称性，促进类似单层和类似双层的朗道能级之间的杂化。 这种带间耦合增强了朗道能级混合因子$\eta$并激活了三体相互作用——这两者都明确地破坏了FQH的PHS。 结果是，传统的FQH态完全不稳定，为以受控方式设计FQH的对称性破缺提供了一条途径。 我们确定TLG中的PHS破坏是外源性的，并与单层和双层石墨烯最低朗道能级中观察到的内在、由相互作用驱动的对称性破缺有根本的不同。 显示英文摘要

摘要： We present a detailed experimental study of the particle-hole symmetry (PHS) of the fractional quantum Hall (FQH) states about half filling in a multiband system. Specifically, we focus on the lowest Landau level of the monolayer-like band of Bernal stacked trilayer graphene (TLG). In pristine TLG, the excitation energy gaps, Land\'e g-factor, effective mass, and disorder broadening of the odd-denominator FQH states are identical to their hole-conjugate counterpart. This precise PH symmetry stems from the lattice mirror symmetry that precludes Landau-level mixing. Introducing a non-zero displacement field \(D\) disrupts this mirror symmetry, facilitating the hybridization between the monolayer-like and bilayer-like Landau levels. This inter-band coupling enhances the Landau level mixing factor $\eta$ and activates three-body interactions -- both of which explicitly break the PHS of FQHs. As a result, conventional FQHs are completely destabilized, offering a route to engineer symmetry breaking of FQHs in a controlled way. We establish that the PHS breaking in TLG is of extrinsic origin and is fundamentally distinct from the intrinsic, interaction-driven symmetry breaking observed in the lowest Landau levels of single-layer and bilayer graphene.