Lattid

Lattid is a hypothetical quasiparticle describing a localized, quantized distortion of a crystalline lattice that can propagate as a stable excitation in nonlinear lattice systems. The concept was introduced in theoretical studies to explore how nonlinearities influence energy transport in nanoscale materials and to distinguish localized lattice distortions from conventional phonons.

In theoretical models, lattids arise as topologically stabilized, breather-like excitations in one- or two-dimensional lattices with strong nonlinear interactions. They are characterized by a finite energy, a well-defined center of distortion, and a propagating velocity that depends on the lattice model and the amplitude of the distortion. Lattids may carry momentum and energy and can interact with defects, phonons, and other lattids, with outcomes that depend on the specifics of the nonlinear coupling and lattice geometry.

Observation and research into lattids focus on simulations and proposed experimental platforms. Possible routes include ultrafast spectroscopy of crystalline solids subjected to targeted excitations, and the use of cold-atom optical lattices that emulate nonlinear lattice dynamics. Detecting a lattid would likely involve tracking localized lattice distortions in real time or inferring their presence from anomalous energy transport or localized vibrational modes.

Etymology and status: the term lattid is not standard in mainstream condensed-matter physics and remains primarily within theoretical discussion and speculative literature. As of 2026, there is no widely accepted experimental confirmation, and lattid concepts are used mainly as a toy model to illustrate how nonlinear localization can affect lattice dynamics and energy transfer.