arXiv:2007.02993 · Physical Review Letters
Mott-Glass Phase of a One-Dimensional Quantum Fluid with Long-Range Interactions
Romain Daviet, N. Dupuis
Abstract
We investigate the ground-state properties of quantum particles interacting via a long-range repulsive potential ${\mathcal{V}}_{\ensuremath{\sigma}}(x)\ensuremath{\sim}1/|x{|}^{1+\ensuremath{\sigma}}$ ($\ensuremath{-}1<\ensuremath{\sigma}$) or ${\mathcal{V}}_{\ensuremath{\sigma}}(x)\ensuremath{\sim}\ensuremath{-}|x{|}^{\ensuremath{-}1\ensuremath{-}\ensuremath{\sigma}}$ ($\ensuremath{-}2\ensuremath{\le}\ensuremath{\sigma}<\ensuremath{-}1$) that interpolates between the Coulomb potential ${\mathcal{V}}_{0}(x)$ and the linearly confining potential ${\mathcal{V}}_{\ensuremath{-}2}(x)$ of the Schwinger model. In the absence of disorder the ground state is a Wigner crystal when $\ensuremath{\sigma}\ensuremath{\le}0$. Using bosonization and the nonperturbative functional renormalization group we show that any amount of disorder suppresses the Wigner crystallization when $\ensuremath{-}3/2<\ensuremath{\sigma}\ensuremath{\le}0$; the ground state is then a Mott glass, i.e., a state that has a vanishing compressibility and a gapless optical conductivity. For $\ensuremath{\sigma}<\ensuremath{-}3/2$ the ground state remains a Wigner crystal.