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A three-terminal device formed by two electrostatic barriers crossing an asymmetrically patterned two dimensional electron gas displays absolute negative resistance in the transport regime where intercarrier scattering dominates [1]. The observed reversal of the current or potential in the middle terminal can be interpreted as the analog of Bernoulli's effect in a Fermi liquid. For a gas of electrons, particles obeying Fermi statistics, under equilibrium conditions the Pauli exclusion principle dictates a uniform momentum distribution in all directions. However when electrons are injected over a barrier this severe restriction is lifted as they are escalated to unpopulated levels. Although electrons cannot stay for long in this nonequilibrium state and momentarily relax, a spatial range of directional hot electrons is created with the addition of a second barrier on the downstream. The narrow angle scattering in two dimensions helps the directionality to be cascaded over several microns. A lead placed along the flow measures a potential depression or a current reversal. Here we report the development of the effect with reduction in the dimensions down to submicron traverse lenghts.
[1] I. Kaya, K. Eberl, Absolute negative resistance induced by directional electron electron scattering in two dimensional electron gas., Phys. Rev. Lett., 98, 186801, 2007. |
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