Dresselhauseffekter

Dresselhaus effect, also known as Dresselhaus spin-orbit coupling, is a spin-dependent interaction that arises in crystals lacking bulk inversion symmetry, notably zinc blende semiconductors such as GaAs and InAs. It originates from the crystal lattice’s lack of inversion symmetry and produces a momentum-dependent effective magnetic field that splits electronic bands even in zero external magnetic field. In three dimensions, the Dresselhaus interaction couples the electron spin to its crystal momentum in a way that the energy splitting is cubic in the electron wave vector components.

In two-dimensional systems, such as electrons confined in quantum wells grown along the [001] direction, k_z is quantized and the expectation value ⟨k_z^2⟩ is fixed, producing an effective linear term in k. This leads to a spin splitting that depends on crystallographic direction and to characteristic spin textures with spins oriented in specific relationships to the momentum. The Dresselhaus effect often competes with the Rashba effect, which arises from structural inversion asymmetry; the combination of the two can enhance or suppress spin splitting depending on direction and can produce anisotropic spin relaxation or persistent spin-helix regimes when parameters are tuned.

The phenomenon is central to semiconductor spintronics, affecting spin transport measurements, quantum-well design, and spin-based devices. It is named after Gene Dresselhaus, who developed the theory of spin-orbit coupling in zinc blende structures.