Spin logic based on persistent spin helices

A spin logic device, comprising:

• an electron confinement layer confining an electron gas in a two-dimensional area (2DEG) subtended by a direction x and a direction y, the latter being perpendicular to the former, the spin logic device being configured for the 2DEG to support a persistent spin helix (PSH) formed therein with a given spin component oscillating with periodicity λ along direction x but not oscillating along direction y;
• and
• a logic circuit, comprising:
• (i) at least one input device, energizable to create respective local spin-polarizations of the 2DEG in respective first regions of the confinement layer, to form respective PSHs;
• and (ii) an output device configured to detect, in a second region of the confinement layer, an average spin-polarization of the 2DEG resulting from one or more local spin-polarizations created by the one or more input devices and diffused through one or more resulting PSHs wherein a projection of a distance (d) between the second region and any one of the first regions onto said direction x is equal to nλ/a, n integer, a equal to 2 or 4.