Charge-neutral atoms (or cold atoms as you may know them) are kept at super low temperatures where their quantum properties become more apparent. One particular thing that these atoms are used for is in emulating the basic behavior of electrons. 

One team that’s been interested in this area explicitly over the past few years is one led by Tilman Esslinger at the Institute of Quantum Electronics in the Department of Physics of ETH Zurich. As part of their research, they developed a platform that took these cold atoms and fed them through 1D and 2D structures. In doing so they are able to study the quantized conductance of the atoms in more detail.

An optical beam (red) introduces an effect equivalent to applying a magnetic field inside an optically defined structure in which the atoms move (green). Atoms in the energetically lower spin state (orange) can flow while atoms in a higher spin state (blue) are blocked. CREDIT ETH Zurich/D-PHYS

This atomic spin filter developed by the ETH researchers is just as efficient as an equivalent system out there currently. And when paired with the controllability of the cold-atom platform, it enables a whole realm of exciting new possibilities for exploring quantum transport in more depth. 

Photo by Zoltan Tasi on Unsplash