Related papers: Interplay of Rotational, Relaxational, and Shear D…
In a neutral system such as liquid helium-3, transport of mass, heat, and spin provide information analogous to electrical counterparts in metals, superconductors and topological materials. Of particular interest is transport in strongly…
We have measured the temperature dependence of the time of flight of helium excimer molecules He2* in superfluid 4He and find that the molecules behave ballistically below 100mK and exhibit Brownian motion above 200 mK. In the intermediate…
Soft solids with tunable mechanical response are at the core of new material technologies, but a crucial limit for applications is their progressive aging over time, which dramatically affects their functionalities. The generally accepted…
We investigate thermal avalanche dynamics in amorphous solids using elastoplastic models with local activation rules and no external driving. Dynamical heterogeneities, quantified through persistence measurements and the associated…
Superfluid helium nanodroplets are often considered as transparent and chemically inert nanometer-sized cryo-matrices for high-resolution or time-resolved spectroscopy of embedded molecules and clusters. On the other hand, when the helium…
A simple phenomenological model is developed for the recent torsional oscillator experiments on solid $^4$He. Within this model, for a homogeneous sample there is a specific quantitative relation between the change in the oscillator's…
In liquid helium 4, many features associated to Bose statistics have been masked by the strongly interacting nature of the liquid. As an example of these features, we examine the shear viscosity of liquid helium 4 above the lambda point.…
A steady shear flow can drive supercooled liquids into a non-equilibrium state. Using molecular dynamics simulations under steady shear flow superimposed with oscillatory shear strain for a probe, non-equilibrium mechanical responses are…
The scattering of atoms and rotons at the free surface of superfluid 4He is studied in the framework of linearised time dependent mean field theory. The phenomenological Orsay-Trento density functional is used to solve numerically the…
We investigate freely cooling systems of rough spheres in two and three dimensions. Simulations using an event driven algorithm are compared with results of an approximate kinetic theory, based on the assumption of a generalized homogeneous…
In the present study, we performed molecular-dynamics simulations and investigated dynamical heterogeneity in a supercooled liquid under a steady shear flow. Dynamical heterogeneity can be characterized by three quantities: the correlation…
We present neutron scattering results for the dynamic response by superfluid and normal-fluid 4He and the results of a simple perturbation-theory analysis which allows us to describe all aspects of the observed behavior by considering only…
We study the hydrodynamics of quantum 4He crystal oscillations in a superfluid liquid with involving the dynamics of atomically rough surfaces. It is shown that, due to enhancement of the kinetic growth coefficient as the temperature…
We have studied spinning superfluid $^4$He nanodroplets at zero temperature using Density Functional theory. Due to the irrotational character of the superfluid flow, the shapes of the spinning nanodroplets are very different from those of…
We study the interaction between tides and convection in astrophysical bodies by analysing the effect of a homogeneous oscillatory shear on a fluid flow. This model can be taken to represent the interaction between a large-scale periodic…
Frequency shifts and dissipations of a compound torsional oscillator induced by solid $^4$He samples containing $^3$He impurity concentrations ($x_3$ = 0.3, 3, 6, 12 and 25 in units of 10$^{-6}$) have been measured at two resonant mode…
Thermal fluctuations, geometric exclusion, and external driving all govern the mechanical response of dense particulate suspensions. Here, we measure the stress-strain response of quasi-two-dimensional flow-stabilized microsphere heaps in a…
The reciprocal energy and enstrophy transfers between normal fluid and superfluid components dictate the overall dynamics of superfluid $^4$He including the generation, evolution and coupling of coherent structures, the distribution of…
We present several exact solutions of the eigenfrequency problem for torsional shear vibrations in homogeneous and non-homogeneous models of the neutron star crust governed by canonical equation of solid mechanics with a restoring force of…
We show that a viscous liquid confined between two low thermal conductive surfaces (Al2O3) emit a thermal response upon applying a low frequency (Hz) shear excitation. Hot and cold thermal waves are observed in situ at atmospheric pressure…