Experimental realization of one dimensional helium.

As the spatial dimension is lowered, locally stabilizing interactions are reduced, leading to the emergence of strongly fluctuating phases of matter without classical analogues. Here we report on the experimental observation of a one dimensional quantum liquid of He using nanoengineering by confining it within a porous material preplated with a noble gas to enhance dimensional reduction. The resulting excitations of the confined He are qualitatively different than bulk superfluid helium, and can be analyzed in terms of a mobile impurity allowing for the characterization of the emergent quantum liquid beyond the Luttinger liquid paradigm.

Shape and size of highly concentrated micelles in CTAB/NaSal solutions by Small Angle Neutron Scattering (SANS).

Highly concentrated micelles in CTAB/NaSal solutions with a fixed salt/surfactant ratio of 0.6 have been studied using Small Angle Neutron Scattering (SANS) as a function of temperature and concentration. A worm-like chain model analysis of the SANS data using a combination of a cylindrical form factors for the polydisperse micellar length, circular cross-sectional radius with Gaussian polydispersity, and the structure factor based on a random phase approximation (RPA) suggests that these micelle solutions have a worm-like micellar structure that is independent of the concentration and temperature.

Structural evolution of the dihydrate to anhydrate crystalline transition of trehalose as measured by wide-angle X-ray scattering.

Wide-angle X-ray scattering measurements were performed to record structural changes during the transition from trehalose dihydrate to crystalline anhydrous alpha-trehalose. The results show that large dihydrate crystals rearrange into smaller sized alpha crystals; from the peak widths we calculate a crystallite size of typically approximately 40 trehalose molecules. We find that the dehydration probably takes place in a two-step process with different time scales for both the water removal step and the molecule rearrangement step.

Monolayer sorption of neon in mesoporous silica glass as monitored by wide-angle x-ray scattering.

We report measurements of the x-ray scattering intensity as mesoporous silica glasses are filled with neon. The intensity of the first peak in the liquidlike diffraction pattern increases nonlinearly with mass adsorbed. We outline a simple model assuming that the major coherent contribution to the first peak in the scattering function S(Q) is due to interference from nearest-neighbor scatterers.