Breakdown of Zero-Energy Quantum Hall State in Graphene in the Light of Current Fluctuations and Shot Noise
We have investigated the cross-over from Zener tunneling of single charge carriers to avalanche type of bunched electron transport in a suspended graphene Corbino disk in the zeroth Landau level. At low bias, we find a tunneling current that follows the gyrotropic Zener tunneling behavior. At larger bias, we find an avalanche type of transport that sets in at a smaller current the larger the magnetic field is. The low-frequency noise indicates strong bunching of the electrons in the avalanches. On the basis of the measured low-frequency switching noise power, we deduce the characteristic switching rates of the avalanche sequence. The simultaneous microwave shot noise measurement also reveals intrinsic correlations within the avalanche pulses and indicate a decrease in correlations with increasing bias.
KeywordsGraphene Quantum Hall Dielectric breakdown Shot noise
We thank C. Flindt, A. Harju, T. Ojanen, S. Paraoanu, and B. Plaçais, for fruitful discussions. This work has been supported in part by the EU Framework Programme (FP7 and H2020 Graphene Flagship), by ERC (Grant No. 670743), and by the Academy of Finland (Project No. 250280 LTQ CoE). A.L. is grateful to Vaisälä Foundation of the Finnish Academy of Science and Letters for a scholarship. This research project made use of the Aalto University OtaNano/LTL infrastructure which is part of European Microkelvin Platform.
- 1.A. Laitinen, M. Kumar, P.J. Hakonen, arXiv:1710.04137 (2017)
- 8.G.E. Volovik, Pis’ma Zh. Eksp. Teor. Fiz. 15, 116 (1972)Google Scholar
- 9.E.B. Sonin, Zh Eksp, Teor. Fiz. 64, 970 (1973)Google Scholar
- 28.M. Kumar, A. Laitinen, P.J. Hakonen, arXiv:1611.02742 (2016)