What is "valleytronics"

n. (context physics English) A proposed equivalent of electronics utilizing (term: valleys) in the valence band or conduction band structure of some semiconductors or insulators that possess multiple valleys, such as graphene, carbon nanotubes, bismuth, dichalcogenides, diamond or silicon.

Valleytronics is a portmanteau combining the terms valley and electronics. The term refers to the technology of control over the valley degree of freedom (a local maximum/minimum on the valence/conduction band) of certain semiconductors that present multiple valleys inside the first Brillouin zone—known as multivalley semiconductors. The term was coined in analogy to the blooming field of spintronics. While in spintronics the internal degree of freedom of spin is harnessed to store, manipulate and read out bits of information, the proposal for valleytronics is to perform similar tasks using the multiple extrema of the band structure, so that the information of 0s and 1s would be stored as different discrete values of the crystal momentum.

The term is often used as an umbrella term to other forms of quantum manipulation of valleys in semiconductors, including quantum computation with valley-based qubits, valley blockade and other forms of quantum electronics. First experimental evidence of valley blockade predicted in Ref. (which completes the set of Coulomb charge blockade and Pauli spin blockade) has been observed in a single atom doped silicon transistor. Several theoretical proposals and experiments were performed in a variety of systems, such as graphene, some Transition metal dichalcogenide monolayers, diamond, Bismuth, Silicon, Carbon nanotubes, Aluminium arsenide and silicene.