  The ground states of bosons have been classified into superfluid, Mott
insulator, and bose glass. Recent experiments in two-dimensional
superconductors strongly suggest the existence of the fourth quantum state of
Cooper pairs, i.e., bose metal or quantum metal, where the resistivity remains
constant at lowest temperature. However, its theoretical understanding remains
unsettled. In this paper, we show theoretically that the bosons in the dilute
limit subject to dissipation can lose the superfluidity and remain metallic,
utilizing the Feynman's picture of superfluidity in the first quantized
formulation. This result is relevant to the quantum vortices under an external
magnetic field in two-dimensional superconductors with the finite resistivity
of the normal core as the source of dissipation.
