Macroscopic suppression of supersonic quantum transport

Abstract

We consider a broad class of strongly interacting quantum lattice gases, including the Fermi-Hubbard and Bose-Hubbard models. We focus on macroscopic particle clusters of size $\hat{I}¸N$, with $\hat{I}¸\in (0,1)$ and $N$ the total particle number, and we study the quantum probability that such a cluster is transported across a distance $r$ within time $t$. Conventional effective light cone arguments yield a bound of the form $\exp (vt-r)$. We report a substantially stronger bound $\exp (\hat{I}¸N(vt-r))$, which provides exponential suppression that scales with system size. Our result establishes a universal dynamical large deviation principle: macroscopic suppression of supersonic macroscopic transport (MASSMAT).

15 pages, 4 figures; v2: final version corresponding to published article