TY - JOUR
T1 - Transition of a two-dimensional spin mode to a helical state by lateral confinement
AU - Altmann, P.
AU - Kohda, M.
AU - Reichl, C.
AU - Wegscheider, W.
AU - Salis, G.
N1 - Publisher Copyright:
© 2015 American Physical Society.
PY - 2015/12/14
Y1 - 2015/12/14
N2 - Spin-orbit interaction enables electrical tuning of spins, thus facilitating spintronics applications. It leads to spin precession about a momentum-dependent spin-orbit field. For a diffusive, two-dimensional electron gas the spin orientation at a given spatial position depends on which trajectory the electron travels to that point. Under increasing lateral confinement the spin orientation becomes independent on the trajectory and the formation of a long-lived helical spin mode is predicted. Here we visualize this transition experimentally in a GaAs quantum-well structure with isotropic spin-orbit interaction. Spatially resolved measurements show the formation of a helical mode already for nonquantized and nonballistic channels. We find a spin-lifetime enhancement that is in excellent agreement with theoretical predictions. Lateral confinement of a two-dimensional electron gas provides an easy-to-implement technique for achieving long spin lifetimes in the presence of strong spin-orbit interaction for a wide range of material systems.
AB - Spin-orbit interaction enables electrical tuning of spins, thus facilitating spintronics applications. It leads to spin precession about a momentum-dependent spin-orbit field. For a diffusive, two-dimensional electron gas the spin orientation at a given spatial position depends on which trajectory the electron travels to that point. Under increasing lateral confinement the spin orientation becomes independent on the trajectory and the formation of a long-lived helical spin mode is predicted. Here we visualize this transition experimentally in a GaAs quantum-well structure with isotropic spin-orbit interaction. Spatially resolved measurements show the formation of a helical mode already for nonquantized and nonballistic channels. We find a spin-lifetime enhancement that is in excellent agreement with theoretical predictions. Lateral confinement of a two-dimensional electron gas provides an easy-to-implement technique for achieving long spin lifetimes in the presence of strong spin-orbit interaction for a wide range of material systems.
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U2 - 10.1103/PhysRevB.92.235304
DO - 10.1103/PhysRevB.92.235304
M3 - Article
AN - SCOPUS:84950336051
VL - 92
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 23
M1 - 235304
ER -