Electronlattice

Electronlattice is a term used in condensed matter physics to describe a periodic arrangement of electronic charge density within a solid. The phrase is not universally defined and is used in different ways by researchers. In some contexts it refers to the electronic part of a crystal, that is, the distribution of electrons moving in the periodic potential created by the stationary ion lattice. In others, it denotes an emergent electronic order in which the electrons themselves form a spatially periodic structure, somewhat independently of the underlying ionic positions.

Two main manifestations are often discussed. The first is a charge density wave (CDW), a periodic modulation of electron density that arises from electron-phonon interactions and Fermi surface nesting in low-dimensional or highly anisotropic materials. The second is a Wigner crystal, a regime at low electron density and weak screening where electrons localize to minimize Coulomb repulsion, effectively forming an electronic lattice.

Key characteristics include a well-defined wavevector of the density modulation, often described by an order parameter and, in the CDW case, the opening of a gap at the Fermi surface. The presence of an electron lattice can strongly affect transport and optical properties and may couple to lattice vibrations, producing phenomena such as phonon anomalies and nonlinear transport.

Experimental and theoretical investigations employ techniques such as diffraction and scattering to detect periodic electron density, scanning tunneling microscopy to image local order, and transport measurements under varying density and temperature. Theoretical descriptions range from mean-field treatments of CDWs to many-body approaches for Wigner crystals. The term electronlattice remains informal in some contexts, with standard terminology typically referring to charge density waves, Wigner crystals, or electronic order.