Fermi Energy Iso-surfaces

This interactive visualization explores theoretical electron energy levels and velocities of a crystalline material. The implementation runs in web pages and uses WebGL2 features which are not supported on all browser configurations. More specifically it shows the Fermi surface of LaNiO3 and its evolution under compressive and tensile biaxial epitaxial strain. In this material, strain induces Lifshitz transitions where parts of the Fermi surface merge or develop holes. The data has been obtained at CCQ using density functional theory (DFT) calculations. Further information on the data, the physics, and the calculations will be available in a journal article currently in process.

The panels display the energy iso-surface in reciprocal momentum space where the electron energy reaches an adjustable energy cut off value. In condensed matter physics, the iso-surface at an energy cut off equal to zero is called the Fermi surface. At zero temperature the Fermi surface separates the occupied electron states from the unoccupied ones. Its characteristic shape is fundamental to understand the electronic properties of crystalline materials.

The left panel displays iso-surfaces colorized by the direction of the surface normal at each vertex.

The middle panel displays iso-surfaces colorized by electron velocity vector at each vertex.

The right panel displays a wireframe of the iso-surface.

Rotate all figures by dragging the mouse over the wireframe on the right.

Adjust top slider to change the energy cutoff value.

Adjust the bottom sliders to slice away parts of the surface.