Related papers: Evidence for a High-Temperature Disorder-Induced M…
Molecules immersed in liquid helium are excellent probes of superfluidity. Their electronic, vibrational and rotational dynamics provide valuable clues about the superfluid at the nanoscale. Here we report on the experimental study of the…
We present data for energy dissipation factor (Q^{-1}) over a broad temperature range at various pressures of a torsion pendulum setup used to study 3He confined in a 98% open silica aerogel. Values for Q^{-1} above T_c are temperature…
We study the thermodynamics of helium at densities relevant for white dwarf physics. We find evidence that, as the temperature is increased, there is first a first order transition between two superconducting phases followed by a second…
We investigate out-of-the equilibrium properties of the electron liquid in a two-dimensional disordered superconductor subject to the electric bias and temperature gradient. We calculate kinetic coefficients and Nyquist noise, and find that…
Oscillating solid bodies have frequently been used for studying the properties of normal and superfluid helium. In particular, the transition from laminar flow to turbulence has attracted much interest recently. The purpose of this note is…
Turbulence in a superfluid in the zero temperature limit consists of a dynamic tangle of quantized vortex filaments. Different types of turbulence are possible depending on the level of correlations in the orientation of vortex lines. We…
The introduction of liquid 3He into silica aerogel provides us a with model system in which to study the effects of disorder on the properties of a strongly correlated Fermi liquid. The transport of heat, mass and spin exhibits cross-over…
Dislocations are shown to be smooth at zero temperature because of the effective Coulomb-type interaction between kinks. Crossover to finite temperature rougnehing is suggested to be a mechanism responsible for the softening of \he4 shear…
In the class of materials called spin liquids, a magnetically ordered state cannot be attained even at milliKelvin temperatures because of conflicting constraints on each spin (for e.g. from geometric or exchange frustration). The resulting…
Supersolid is a mysterious and puzzling state of matter whose possible existence has stirred a vigorous debate among physicists for over 60 years. Its elusive nature stems from the coexistence of two seemingly contradicting properties,…
Solid rigidity and liquid-scale mobility are thought incompatible in elemental substances. One cannot have an elemental solid that is long-range positionally ordered wherein the atoms flow like in a liquid simultaneously. The only exception…
We model the low-temperature specific heat of solid $^4$He in the hexagonal closed packed structure by invoking two-level tunneling states in addition to the usual phonon contribution of a Debye crystal for temperatures far below the Debye…
We have carried out torsional oscillator (TO) and heat capacity (HC) measurements on solid 4He samples grown within a geometry which restricts the helium to thin (150 um) cylindrical discs. In contrast to previously reported values from…
Samples of PbS$_x$Se$_y$Te$_{1-x-y}$, Pb$_{1-x}$Sn$_x$Te$_{1-y}$Se$_y$, and Pb$_{1-x}$Sn$_x$Te$_{1-y}$S$_y$ quaternary solid solutions were investigated in the 4--200~K temperature range using electrical and X-ray methods. The regions where…
Mixed $^3$He-$^4$He droplets created by hydrodynamic instability of a cryogenic fluid-jet may acquire angular momentum during their passage through the nozzle of the experimental apparatus. These free-standing droplets cool down to very low…
We argue that charges in underdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$ move in a dissipative environment of strong spatial and temporal fluctuations. The unusual temperature dependence of the Hall angle known as "the separation of lifetimes" is…
Recent experiments have shown remarkable dynamics of solid $^4$He melting and growth, driven by the normal incidence of an acoustic pulse on the solid-liquid interface. The theory of solid growth/melting, driven by the radiation pressure of…
We report studies of the growth of solid hcp \4he at pressures higher than the bulk freezing pressure using a cell design that allows us to inject atoms into the solid. Near the melting curve during injection we observe random events during…
The rigid double-torus torsional oscillator (TO) is constructed to reduce any elastic effects in-herent to complicate TO structures, allowing explicit probing for a genuine supersolid signature. We investigated the frequency- and…
We study the zero-temperature quantum phase transition between liquid and hcp solid helium-4. We use the variational method with a simple yet exchange-symmetric and fully explicit wavefunction. It is found that the optimized wavefunction…