Research Status

There is now widespread interest in whether some electron fluids exhibit viscosity. Key evidence for this phenomenon comes from studied of ultra-pure dellafossite crystals (A.P. Mackenzie, Rep. Prog. Phys. 80, 032501 (2017)).

Fig. 6 All familiar viscous fluid flow in the geometry(L): viscosity (n): density (r) regime that exceeds Reynolds number R=ρvL/n~3000, generates turbulence. Here the viscous flow from left to right past an obstacle generates a vortex train.

Research Plans

A profound challenge for this field is to detect turbulence of an electronic fluid. No phenomena e.g. Fig. 6 have ever been observed for any electron fluid. Thus, exploratory studies to visualize viscous phenomena in an electron fluid are of great interest.

a) We plan to attempt visualize the impurity scattering interference in Co-dellafossite crystals whose Fermi surface is already very well understood. Subsequently, a large electric current generating (electron fluid flow) will be applied and its effects visualized directly at atomic scale (in a conventional electron gas no detectable effects would be expected).

b) If effects of electron fluid flow are observable, then the Reynolds number for an atomic scale perturbation will be used to predict the current density necessary to cause turbulence, for which we will then search.