Microwave photons emitted by fractionally charged quasiparticles

Two-dimensional systems at low temperatures and high magnetic fields can host exotic particles called “anyons” that are very different from bosons and fermions. They carry a fractional charge and have fractional statistics^1,2. Their fractional charge has been studied successfully using low-frequency shot noise measurement³. However, the experimental outcomes intertwined with the scattering properties of the conductor⁴. Here, by measuring the high-frequency noise generated by the partitioning of a continuous stream of anyons, we probe the fractional charge, independent of details of the quantum conductor. The high-frequency noise is suppressed above the cutoff frequency f related to the applied dc bias V by a Josephson type relation: f=e^*V/h, where e^* is the fractional charge. This provides direct evidence of fractional charge of anyons^5,6.
Ref:
1. Tsui, D. C.et al., PRL. 48, 1559, 1982
2. Leinaas and J. Myrheim, Nuovo Cimento Soc. Ital. Fis.B 37, 1, 1977
3. de Picciotto, R., et al. Nature 389, 162, 1997.
4. Reznikov, M., et al. Nature 399, 238, 1999
5. Bisognin,R et al. Nature Comm, 10, 1708, 2019
6. Kapfer, M. et al. Science 363, 846, 2019