Controlling anyon fluctuations in a graphene quantum Hall interferometer

Recent work has unveiled dynamically fluctuating quasiparticles within graphene-based quantum Hall interferometers [1,2]. While this phenomenon proved valuable for observing abelian anyon braiding in odd-denominator fractional quantum Hall states, the origin of the quasiparticle fluctuations and consequent random telegraph noise interference signal remained largely unexplained. Here, we demonstrate that the fluctuations are dependent on incident thermal radiation from higher temperature stages of the cryostat, and hence can be strongly suppressed by increasing sample shielding at base temperature. In addition, we demonstrate how the number of anyons contained within the device can be controlled by incident microwave radiation. Photon-based control of localized anyons may be valuable for probing non-abelian anyons in even-denominator states and for constructing tunable gates and quantum bits with topological states.

[1] T. Werkmeister, J. R. Ehrets, M. E. Wesson, D. H. Najafabadi, K. Watanabe, T. Taniguchi, B. I. Halperin, A. Yacoby, and P. Kim, Anyon braiding and telegraph noise in a graphene interferometer. (2024), arxiv:2403.18983 [cond-mat].

[2] N. L. Samuelson, L. A. Cohen, W. Wang, S. Blanch, T. Taniguchi, K. Watanabe, M. P. Zaletel, and A. F. Young, Anyonic statistics and slow quasiparticle dynamics in a graphene fractional quantum Hall interferometer (2024), arxiv:2403.19628 [cond-mat].