A general scenario that leads to Coulomb quantum criticality with the dynamical critical exponent z=1 is proposed. I point out that the long-range Coulomb interaction and quenched disorder have competing effects on z, and that the balance between the two may lead to charged quantum critical points at which z=1 exactly. This is illustrated with the calculation for the Josephson junction array Hamiltonian in dimensions D=3-\epsilon. Precisely in D=3, however, the above simple result breaks down, and z>1. Relation to other theoretical studies is discussed.
A general scenario that leads to Coulomb quantum criticality with the dynamical critical exponent
z=1 is proposed. I point out that the long-range Coulomb interaction and quenched disorder have competing effects on
z, and that balance between the two may lead to charged quantum critical points at which
z=1 exactly. This is illustrated with the calculation for the Josephson junction array Hamiltonian in dimensions $D\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3\ensuremath{-}\ensuremath{\epsilon}$. Precisely in
D=3, however, the above simple result breaks down, and
z>1. Relation to other studies is discussed.