Cube‐root broadening of surface‐charge packets Available to Purchase

The width of a surface‐charge packet in the proximity of a conducting sheet increases asymptotically only as the cube root of the time due to space‐charge repulsion. By contrast, thermal diffusion broadens as the square root of the time, and is otherwise negligible here. The cube‐root behavior is invariant over a wide range of transverse and normal electric fields, and may have significant implications for the minimum spatial variation of charge density achievable in devices.