The Fermi surface is a concept in condensed matter physics that describes the surface in momentum space (or reciprocal space) defining the boundary between filled and empty quantum states at absolute zero temperature in a solid material.
In simpler terms, it represents the collection of momentum states that electrons occupy in a material when the temperature is at absolute zero (0 Kelvin or -273.15°C).
Key points about the Fermi surface:
Energy Levels and States: According to the Pauli Exclusion Principle, no two electrons in a solid can occupy the same quantum state. At absolute zero, electrons fill up energy levels starting from the lowest energy states. The Fermi surface separates these filled states (below the surface) from empty states (above the surface).
Properties of Materials: The Fermi surface properties are crucial in determining various electronic and thermal properties of materials. It helps in understanding electrical conductivity, heat capacity, and other electronic behaviors.
Complexity and Shape: The Fermi surface can have complex shapes in different materials, including spheres, ellipsoids, or more intricate structures depending on the material’s electronic band structure.
