Princeton physicists have directed the flow of electrons at will using a scanning tunneling spectromicroscope with a rotatable magnetic field. [See image].  “The spectromicroscope has a resolution less than half the size of an atom, allowing it to scan individual atoms and detect details of their electrons while measuring the electrons’ energy and spin distribution.”   This capability resulted in the discovery of the tunable electron flow direction.  “This level of manipulability opens enormous possibilities for next-generation nanotechnologies and quantum computing.”  This report is found here at ScienceDaily…

“When the Princeton researchers turn an external magnetic field in different directions (indicated with arrows), they change the orientation of the linear electron flow above the kagome (six-fold) magnet, as seen in these electron wave interference patterns on the surface of a topological quantum kagome magnet. Each pattern is created in the lab of Princeton Professor Zahid Hasan by a particular direction of the external magnetic field applied on the sample.”  (Image Credit: M. Z. Hasan, Jia-Xin Yin, Songtian Sonia Zhang, Princeton University)