Recent, in articles on QFT and condensed matter new objects appear -- fractons.

As I understand now, fracton is a particle with restricted motion: for example, such excitations can move only along line.

  1. If such excitations have restricted motion, how they deal with uncertainty principle?

  2. Could somebody present simple model, where such excitations appear?

  3. Also, it is very interesting to understand, which role such excitations play in condensed matter systems?


These[1][2] review papers contain good introductions to fractons.

  1. Generally, there is no uncertainty principle for such systems. This is because these fractons are usually emergent particles. For example, we can think of a domain wall excitation in a 1D Ising model as a particle, but this does not have any uncertainty principle associated to it.

  2. The prototype model for fractons is the X-cube model (gapped). Another class of models can be constructed using tensor gauge theories (gapless). Both of these are discussed in those papers and references therein.

  3. These systems have many interesting properties. The constrained motion of these excitations make thermalization slow and the dynamics glassy (here), can be used as a system to store quantum information due to its robust sub-extensive ground state degeneracy, and also has interesting connections to toy models of gravity (here). It is also interesting because it is really a new phase of matter we haven't seen before, and has expanded the problem of classification of phases of matter. I am not aware of any experimental realizations of fractons as of now.

| cite | improve this answer | |

Not the answer you're looking for? Browse other questions tagged or ask your own question.