Hydrodynamic charge transport
Due to internal scattering processes, heat and charge transport in traditional materials is mostly diffusive. However, under favorable circumstances, an exotic transport regime characterized by coherent charge and heat transport is observable. These conditions include a low temperature, a pronounced anisotropy, a re-duced dimensionality, and a highly reduced inelastic scattering, and result in electrons and phonons obeying similar physical laws as classical fluid dynamics. Discovered more than 50 years ago for thermal transport (“second sound”), signatures of the hydrodynamic transport regime have recently also been demonstrated in 2D materials (graphene or 2DEGs) and anisotropic 3D materials (PdCoO2, WP2) for both charge and heat transport.
As part of the Hydronics team, our focus is to investigate charge transport in the hydrodynamic regime. The major goals of this project are:
- To understand the properties/descriptors which determine whether a material will be hydrodynamic or not. Some have emerged (low dimensions, clean samples, low T), however, a better understanding of the quantitative balance between different scattering mechanisms is necessary.
- Smoking gun evidences of hydrodynamic charge transport.
- Exploiting hydrodynamic effects for technological applications.
- Exploring the role of device boundaries on the hydrodynamic transport regime.
Collaborators in Laboratory: Dr. Mickael L. Perrin, Prof. Dr. Michel Calame
External partners: Dr. Bernd Gotsmann (IBM research), Prof. Ilaria Zardo (University of Basel), Prof. Nicola Marzari (EPFL).
Funding: This project is funded by the SNF Sinergia project Hydronics.
- De Jong, M. J. M., and L. W. Molenkamp. "Hydrodynamic electron flow in high-mobility wires." Physical Review B 51.19 (1995): 13389.
- Levitov, Leonid, and Gregory Falkovich. "Electron viscosity, current vortices and negative nonlocal re-sistance in graphene." Nature Physics 12.7 (2016): 672-676.
- Bandurin, D. A., et al. "Negative local resistance caused by viscous electron backflow in graphene." Sci-ence 351.6277 (2016): 1055-1058.
- Moll, Philip JW, et al. "Evidence for hydrodynamic electron flow in PdCoO2." Science 351.6277 (2016): 1061-1064.
- Kumar, R. Krishna, et al. "Superballistic flow of viscous electron fluid through graphene constrictions." Nature Physics 13.12 (2017): 1182-1185.
- Gooth, J., et al. "Thermal and electrical signatures of a hydrodynamic electron fluid in tungsten diphos-phide." Nature communications 9.1 (2018): 1-8.