Quantum computing requires the ability to write and read quantum information on the spinors of electrons. This work considers mobile electrons, which move through mesoscopic (or molecular) quantum wire networks. Combining spin-orbit interactions (tunable by external gate voltages), and the Aharonov-Bohm flux (tunable by an external magnetic field), one can have a spin filter: for arbitrary incoming electrons, the outgoing electrons are polarized along a desired direction. This amounts to 'writing' the desired information on the spinor of the electrons. (a) Specific results will be presented for a simple closed interferometer. (b) The above filtering is robust against leaking of electrons, in an open interferometer. Leakage breaks time-reversal symmetry, and can thus replace the magnetic flux. (c) At a given electron energy, filtering can be achieved by tuning two gate voltages. (d) Filtering can also be achieved for a single one-dimensional chain which has spin-orbit interactions, when the chain vibrates in the transverse direction. (e) Such a single wire can also change the Josephson current between two superconductors. (f) Transient time-dependent polarizations can be generated even without a magnetic flux. (g) Similar considerations explain the spin splitting of electrons going through helical organic molecules.
 

Born Jerusalem, 1943. B. Sc. And M. Sc. Hebrew University, Ph. D. Tel Aviv University (1971). Postdoc at Cornell, Harvard, University of California San Diego and Bell Laboratories. Professor of Physics and Nussenzveig chair on statistical physics at Tel Aviv University 1975-2006, now Professor emeritus. Professor of Physics at Ben Gurion University of the Negev 2006-2013, now distinguished professor emeritus. Was an adjunct professor at the University of Oslo, 1985-2013. Held visiting positions at Harvard, MIT, IBM Laboratories, University of Tokyo, NCKU (Taiwan) and more. Wrote more than 430 publications, with more than 36000 citations (h-index 80) on phase transitions, critical phenomena, magnetism, liquid crystals, fractals, percolation, mesoscopic physics and spintronics. Received the Landau, Weizmann and Rothschild prizes in Israel, the Fulbright scholarship in the US, the Humboldt prize in Germany and the Randers prize in Norway. Is a fellow of the American physical society and of the British Institute of physics, a foreign fellow of the American academy of arts and sciences, of two Norwegian academies (Oslo and Trondheim), and of the European academy (Paris), and a member of the Israeli academy of sciences.