Quantum interfacial phenomena in nanoscale water flows: unconventional friction and hydrodynamic Coulomb drag*

Quantum effects are scarce in soft matter systems, where the dynamics are typically described using some version of Newton’s equations. Yet, as the study of water flows is pushed to smaller and smaller scales, there appear phenomena that defy understanding in terms of classical theories of fluid transport. In particular, there is growing evidence for the coupling between fluid flows at the nanoscale and the electronic properties of the confining walls, resulting in both unconventional friction [1] and generation of electric currents inside the wall material [2]. In this talk, I will present some of our latest work on such quantum interfacial dynamics. Starting from the pioneering theoretical work on quantum friction [3], I will discuss the remarkable features of this phenomenon when water flows are confined down to the angström scale. I will then show how the framework of friction is generalized to account for current generation, through a mechanism that we call hydrodynamic Coulomb drag. Finally, I will discuss the favorable comparison between our theoretical predictions and recent experimental data.

[1] Secchi et al., Nature 537, 210-213 (2016)

[2] Gosh et al., Science 299, 1042-1044 (2003)

[3] Kavokine et al. to appear in Nature (2021)