  We investigate quantum fluctuations in thin superconducting wires. We
demonstrate that quantum phase slips dominate the system behavior at low
temperatures and are well in the measurable range for sufficiently thin wires.
We discuss the effect of dissipation, predict a new quantum
superconductor-to-metal (insulator) phase transitions for wires with
thicknesses in the 10-nm range, evaluate the resistance R(T) of such wires and
compare our results with recent experimental findings.
