Researchers create the first single-atom optical switch - Potential device could be possible in a few years

02/03/2016 - 06:28

Dexter Johnson

You may have heard of the single-atom transistor that thumbed its nose at Moore’s Law once and for all. But that transistor was based on the electron, a relative slow poke. What if you could develop a single-atom transistor based on the movement of photons, which travel at the speed of light?



Ref: Atomic Scale Plasmonic Switch. Nano Letters (15 December 2015) | DOI: 10.1021/acs.nanolett.5b04537


The atom sets an ultimate scaling limit to Moore’s law in the electronics industry. While electronics research already explores atomic scales devices, photonics research still deals with devices at the micrometer scale. Here we demonstrate that photonic scaling, similar to electronics, is only limited by the atom. More precisely, we introduce an electrically controlled plasmonic switch operating at the atomic scale. The switch allows for fast and reproducible switching by means of the relocation of an individual or, at most, a few atoms in a plasmonic cavity. Depending on the location of the atom either of two distinct plasmonic cavity resonance states are supported. Experimental results show reversible digital optical switching with an extinction ratio of 9.2 dB and operation at room temperature up to MHz with femtojoule (fJ) power consumption for a single switch operation. This demonstration of an integrated quantum device allowing to control photons at the atomic level opens intriguing perspectives for a fully integrated and highly scalable chip platform, a platform where optics, electronics, and memory may be controlled at the single-atom level.