We infer the magnitude of the superfluid gap for He in aerogel from measurements of the normal fluid density as a function of temperature. We compute the effective Yosida function for two different aerogel samples over a range of pressures. We find that the suppression factor of the zero-temperature superfluid gap, scaled by kBTc , ranges from 0.5 to 0.8 as compared to the pressure-dependent we...

We report the observation of negative magnetoresistance in the ferromagnetic semiconductor Ga1−xMnxAs, x=0.05–0.08, at low temperatures T 3 K and low magnetic fields 0 B 20 mT . We attribute this effect to weak localization. Observation of weak localization strongly suggests impurity band transport in these materials, since for valence band transport one expects either weak antilocalization due...

Administration of the various anesthetic agents including barbiturates results in a dose-related reduction in CMRO2 and cerebral blood flow. The maximum reduction occurs with the dose that results in electrocerebral silence. At this point, energy utilization associated with EEG activity has been reduced to zero, but energy utilization for cellular homeostasis persists unchanged. Additional barb...

We investigate the temperature dependence of the instanton content of gluon fields and their contribution to quark correlation using quenched lattice QCD and the cooling method. We found a suppression of the topological susceptibility at finite temperature, agreeing with the PCAC expectation at low temperature and enhanced suppression for temperatures at and above the deconfinement transition. ...

The problem of unstable particle decay is discussed to show how elementarity of a subsystem immersed in an infinitely larger environment is lost. The decay law, when the same kind of particles as decay product make up a thermal medium, is worked out in detail. The relic abundance of unstable particles does not suffer from the Boltzmann suppression crucial at very low temperatures, because the o...

Electrical resistivity measurements performed on a single crystal of erbium as a function of temperature and hydrostatic pressure have provided a preliminary p–T phase diagram. The results have been interpreted in terms of a model for the magnetic structures of Er deduced from neutron diffraction studies at ambient pressure. This model predicted the existence of a magnetic structure with a wave...

The low-temperature thermal conductivity κ0/T of d-wave superconductors is generally thought to attain a “universal” value independent of disorder at sufficiently low temperatures, providing an important measure of the magnitude of the gap slope near its nodes. We discuss situations in which this inference can break down because of competing order, and quasiparticle localization. Specifically, ...

We have investigated the suppression of single-electron charging effects in metallic single-electron transistors when the conductance of the tunnel junctions becomes larger than the conductance quantum e2yh. We find that the Coulomb blockade of the conductance is progressively shifted at lower temperatures. The experimental results agree quantitatively with the available 1yT expansion at high t...

Transverse-field μSR shifts and relaxation rates have been measured in the non-Fermi liquid (NFL) alloy system UCu5−xPtx, x = 1.0, 1.5, and 2.5. At low temperatures the fractional spread in Knight shifts δK/K ≈ δχ/χ is & 2 for x = 1, but is only half this value for x = 1.5 and 2.5. In a disorder-driven scenario where the NFL behavior is due to a broadly distributed (Kondo or Griffiths-phase clu...