Topological protection in a Landau flat band at v = 7/11, a candidate filling factor for unconventional correlations.

Abstract

Strong interactions in Landau flat bands are known to stabilize correlated states that do not form in other types of flat bands. We report hallmarks of topological protection at the Landau level filling factor $v=7/11$ in a 2D electron system. The $v=7/11$ filling factor is the particle-hole conjugate of $v=4/11$ , a filling factor intensely studied for the possibility of realizing unconventional electronic correlations. Our data establish a new instance for an unusual fractional quantum Hall state and opens up possibilities for the study of unconventional correlations in an enlarged parameter space. We report and discuss transport signatures developing at other filling factors of interest $v=11/17,5/8$ , and $8/13$ , which however in our sample do not exhibit topological protection.