Résumé |
The presence of global conserved quantities in interacting many-body systems
generically leads to diffusive transport at late times. Here we show that this
general principle is substantially modified in systems that conserve in
addition the dipole moment of an associated global charge, in that transport
becomes subdiffusive instead. Such dipole conserving systems are relevant for
fracton phases of quantum matter, that are characterized by excitations with
restricted mobility. Modeling the time evolution of dipole conserving systems,
and higher moment generalizations thereof, such as cellular automata, we
numerically find distinct anomalous exponents of the late time relaxation. We
explain these findings by analytically constructing a general hydrodynamic
model, yielding an accurate description of the scaling form of charge
correlation functions. We will furthermore analyze the spatial profile of the
correlations and discuss experimentally relevant signatures of such higher-
moment conservation. |