title: Enhancement of the quantum-liquid phase by increased resistivity in thick a-MoxSi1-x films.
abstract: Effects of normal-state resistivity rho(n) on the vortex phase diagram at low temperature T have been studied based on dc and ac complex resistivities for thick amorphous MoxSi(1-x) films. It is commonly observed irrespective of rho(n) that, in the limit T=0, the vortex-glass-transition line B(g)(T) is independent of T and extrapolates to a field below the T=0 upper critical field B(c2)(0), indicative of the quantum-vortex-liquid (QVL) phase in the regime B(g)(0)<B<B(c2)(0). The relative width of the QVL phase increases along the B and T axes approximately proportional to rho(n). This result is consistent with a view that the QVL phase is caused by strong quantum fluctuations, which are enhanced with increasing rho(n).
authors.affiliation: Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1, Ohokayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Okuma
authors.forename: S
authors.initials: S
authors.lastname: Togo
authors.forename: M
authors.initials: M
authors.lastname: Morita