Condensed Matter Seminar: Even & odd denominator quantum Hall interferometry in bilayer graphene

Anyons are quasiparticles that obey exchange statistics distinct from those of fermions and bosons. These exotic particles can be realized within the framework of the fractional quantum Hall effect (FQHE), representing a highly coveted goal in condensed matter physics.

In this talk, I will present our group’s recent efforts in exploring anyons within bilayer graphene-based van der Waals heterostructures. I will begin by discussing the FQH phase-space in bilayer graphene, highlighting its rich landscape of topological orders, including various non-Abelian states [1,2]. Following this, I will shift the focus to our interferometry studies at both odd- and even-denominator filling fractions, aimed at detecting the exchange statistics of Abelian and non-Abelian anyons [3,4].

[1] R. Kumar, A. Haug, et al., Quarter- and half-filled quantum Hall states and their competing interactions in bilayer graphene, Nature Comm. (2025)

[2] A. Haug, R. Kumar, et al., Interaction-driven quantum phase transitions between topological and crystalline orders of electrons, arXiv: 2504.18626

[3] J. Kim, H. Dev, et al., Aharonov–Bohm interference and statistical phase-jump evolution in fractional quantum Hall states in bilayer graphene, Nature Nano. (2024)

[4] J. Kim, H. Dev, et al., Aharonov-Bohm Interference in Even-Denominator Fractional Quantum Hall States, arXiv: 2412.19886