User:SpinHE/sandbox

The Spin Hall Effect (SHE) is a transport phenomenon predicted by Russian physicists Mikhail Dyakonov and Vladimir Perel in 1971. It consists in the appearance of spin accumulation on the lateral surfaces of a sample carrying electric current, the signs of the spin directions being opposite on the opposing boundaries. In a cylindrical wire, the current-induced surface spins will wind around the wire. When the current direction is reversed, the directions of surface spin orientation are also reversed.

[The SHE is a transport phenomenon predicted by Russian physicists Mikhail Dyakonov and Vladimir Perel in 1971.[1][2] and consisting in the appearance of spin accumulation on the lateral surfaces of a sample carrying electric current. The opposing surface boundaries have spins of opposite sign. It is somewhat similar to the normal Hall effect, where charges of opposite sign appear on the opposing lateral surfaces in an electric-current carrying sample in a magnetic field. In the case of the Hall effect the charge build up at the boundaries is due to the Lorentz force acting on the charge carriers in the sample due to the magnetic field. No magnetic field is needed for the SHE which is a purely spin-based phenomenon.]

The SHE belongs to the same family as the anomalous Hall effect, known for a long time in ferromagnets, which also originates from spin-orbit interaction.[3]

History

Predicted by Russian physicists Mikhail Dyakonov and Vladimir Perel in 1971.[1][2]

The term "Spin Hall Effect" was introduced by Jorge Hirsch[4] in 1999. It is somewhat similar to the normal Hall effect, where charges of opposite sign appear on the opposing lateral surfaces in an electric-current carrying sample in a magnetic field. In the case of the Hall effect the charge build up at the boundaries is due to the Lorentz force acting on the charge carriers in the sample due to the magnetic field. No magnetic field is needed for the SHE which is a purely spin-based phenomenon. Unaware of the work of Dyakonov and Perel, Hirsch used subtle physical reasoning based on the anomalous Hall effect to predict both the SHE and the inverse SHE. Averkiev and Dyakonov had earlier predicted the SHE [N.S. Averkiev and M.I. Dyakonov, JETP Lett. 35, 196 (1983)], and it had been observed [A.A. Bakun et al., JETP Lett. 40, 1293 (1984)].

Experimentally, the Spin Hall Effect was observed in semiconductors [5][6] more than 30 years after the original prediction. Properties

The origin of SHE is in the spin-orbit interaction, which leads to the coupling of spin and charge currents: an electric current induces a transverse spin current (a flow of spins), which, in turn, leads to an accumulation of spins of opposite signs on opposing lateral boundaries. [1][2][7] One can intuitively understand this effect by using the analogy between an electron and a spinning tennis ball, which deviates from its straight path in air in a direction depending on the sense of rotation (the Magnus effect).