Molecular anyons in the fractional quantum Hall effect

Our high-precision microscopic calculations reveal that fractional quantum Hall (FQH) quasiparticles can often bind into stable clusters, which we call molecular anyons [1], despite the expected Coulomb repulsion between like-charged quasiparticles. The total charge, binding energy, and size of these molecules depend sensitively on the parent FQH state and the electron-electron interaction, which is experimentally tunable, e.g., by varying the quantum well width. Our calculations further suggest that the charge-e/4 non-Abelian anyons of the ν=5/2 FQH state may also bind to form charge-e/2 Abelian molecules. The existence of such molecules may provide a natural explanation for puzzling experimental observations: shot-noise and interference experiments sometimes measure charges that are multiples of the elementary charge at very low temperatures, but resolve the elementary charge at somewhat elevated temperatures [2–5]. These findings lead to a host of new predictions for future experiments and invite a reanalysis of many past ones.

[1] M. Gattu and J. K. Jain, Phys. Rev. Lett. (in press), arXiv:2505.22782.

[2] B. Ghosh, M. Labendik, V. Umansky, et al., Nature 642, 922 (2025).

[3] Y. C. Chung, M. Heiblum, and V. Umansky, Phys. Rev. Lett. 91, 216804 (2003).

[4] A. Bid, N. Ofek, M. Heiblum, V. Umansky, and D. Mahalu, Phys. Rev. Lett. 103, 236802 (2009).

[5] S. Biswas, R. Bhattacharyya, H. K. Kundu, A. Das, M. Heiblum, V. Umansky, M. Goldstein, and Y. Gefen, Nat. Phys. 18, 1476 (2022).