Focus on the Rashba Effect
Figure 1.8: Properties of the Rashba energy spectrum. Panel a) Portion of the energy spectrum of a Hamiltonian containing a Rashba interaction (1.10). Panel b) The Fermi contours relative to the Hamiltonian (1.10), the spin states are indicated. Panel c) section of the energy spectrum for a free electron. Panel d) section of the energy spectrum for an electron in presence of a magnetic field ( Zeeman slitting). Panel e) section of the energy spectrum for an electron in presence of Rashba spin-orbit in teraction. [From D. Bercioux, Spin-Dependent Transport in Nanostructures. PhD thesis, Università degli studi di Napoli Federico II, 2004.]
The Rashba effect, discovered in 1959 by a Soviet-American theoretical physicist Emmanuel Rashba, now a Harvard Physics Research Scholar, continues to supply fertile ground for fundamental research and applications. It provided the basis for the proposal of the spin transistor by Datta and Das in 1990, which has largely inspired the broad and dynamic field of spintronics. More recent developments include new materials for the Rashba effect such as metal surfaces, interfaces and bulk materials. It has also given rise to new phenomena such as spin currents and the spin Hall effect, including its quantized version, which has led to the very active field of topological insulators. The Rashba effect plays a crucial role in yet more exotic fields of physics such as the search for Majorana fermions at semiconductor-superconductor interfaces and the interaction of ultracold atomic Bose and Fermi gases. Advances in our understanding of Rashba-type spin-orbit couplings, both qualitatively and quantitatively, can be obtained in many different ways.
New Journal of Physics has produced a focus collection of articles on the Rashba effect. Read the Editorial which gives a brief account on the history of the Rashba effect, including material that was previously not easily accessible.
[Abstract reprinted under Creative Commons Attribution 3.0 license from G. Bihlmayer, O. Rader and R. Winkler, "Focus on the Rashba Effect," 2015 New J. Phys. 17 050202.]