Spontaneous spin polarization of ballistic electrons in singlehyphen;mode quantum wires due to spin splitting

摘要

We show that a quantumhyphen;wire device with spin splitting can work as an active spin polarizer. Hot electrons in one lsquo;lsquo;spinrsquo;rsquo; subband (e.g., lsquo;lsquo;spin uprsquo;rsquo;) may pass such a device with weak electron pair scattering, while electrons in the opposite subband (lsquo;lsquo;spin downrsquo;rsquo;) may have high conversion probability into the spinhyphen;up subband, resulting in spin polarization of a hot electron beam. Under different circumstances a hot electron beam passing through a singlehyphen;mode quantum wire may induce a steady state magnetization of the background electron gas in a section of the wire weakly coupled to the environment.