# Spin Filtering: how to write and read quantum

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 networks (made of quantum wires or of arrays of quantum dots). Combining spin-orbit interactions, whose strength can be tuned by external gate voltages, and the Aharonov-Bohm flux, which can be tuned by an external magnetic field, one can manipulate the properties of such networks, so that the outgoing electrons are polarized along a desired direction. This amounts to '*writing*' the desired information on the spinor of the electrons. Given a beam of polarized electrons, the *charge conductance *of the same network depends on their polarization, allowing '*reading*' the qubit information. Specific results will be presented for a simple closed interferometer [1]. The talk will also report on more recent work:

(a) The above filtering is robust against leaking of electrons, in an open interferometer [2]. (b) Filtering can also be achieved for a single one dimensional chain which has spin-orbit interactions, when the chain vibrates in the transverse direction [3].

[1] A. Aharony, Y. Tokura, G. Z. Cohen, O. Entin-Wohlman, and S. Katsumoto, *Filtering and analyzing mobile qubit information via Rashba-Dresselhaus- **Aharonov-Bohm interferometers, *Phys. Rev. B **84**, 035323 (2011);(arXiv:1103.2232)

[2] S. Matityahu, A. Aharony, O. Entin-Wohlman and S. Katsumoto, *Robustness of spin filtering against current leakage in a Rashba-Dresselhaus-Aharonov-Bohm interferometer, *Phys. Rev. B 87, 205438 (2013); (arXiv:1302.6772)

- Last modified: 30/05/2013