Researchers from Sweden's Uppsala university and from UK's Element Six have demonstrated electrical valley control in 3D dual-gate diamond field-effect transistors.

Electron density in different valleys after electron injection in a dual-gate valleytronic transistor (Uppsala university)

The team has fabricated valley transistors on single-crystalline diamond plates with ultra-low nitrogen impurity concentrations. A dual-gate configuration was used to gain a high degree of freedom of the control of the valley currents. The control of location and time of the valley-polarized currents was achieved by adding multiple drain electrodes.

Diamonds are a wide-bandgap semiconductor with attractive properties such as high thermal conductivity, high breakdown field, high carrier mobility and chemical inertness. These properties make diamonds potential materials for future valleytronic devices.