Evidence for a Spatially Modulated Superfluid Phase of

In superfluid ^{3}He-B confined in a slab geometry, domain walls between regions of different order parameter orientation are predicted to be energetically stable. Formation of the spatially modulated superfluid stripe phase has been proposed. We confined ^{3}He in a 1.1 µm high microfluidic cavity and cooled it into the B phase at low pressure, where the stripe phase is predicted. We measured the surface-induced order parameter distortion with NMR, sensitive to the formation of domains. The results rule out the stripe phase, but are consistent with 2D modulated superfluid order.

Surface-induced order parameter distortion in superfluid ³He-B measured by nonlinear NMR.

The B phase of superfluid 3He is a three-dimensional time-reversal invariant topological superfluid, predicted to support gapless Majorana surface states. We confine superfluid 3He into a thin nanofluidic slab geometry. In the presence of a weak symmetry-breaking magnetic field, we have observed two possible states of the confined 3He-B phase manifold, through the small tipping angle NMR response. Large tipping angle nonlinear NMR has allowed the identification of the order parameter of these states and enabled a measurement of the surface-induced gap distortion. The results for two different quasiparticle surface scattering boundary conditions are compared with the predictions of weak-coupling quasiclassical theory. We identify a textural domain wall between the two B phase states, the edge of which at the cavity surface is predicted to host gapless states, protected in the magnetic field.

Bilayer 3He: a simple two-dimensional heavy-fermion system with quantum criticality.

Two-dimensional helium-3 (3He) provides a simple model for the experimental investigation of the emergence of quantum complexity in a strongly correlated Fermi system. We have observed two-dimensional, two-band heavy-fermion behavior in bilayer films of 3He atoms when adsorbed on the surface of graphite preplated by a solid bilayer of 4He. Thermodynamic measurements on this system showed that the relevant control parameter is the total density of the 3He film. The 3He bilayer system can be driven toward a quantum critical point at which the effective mass appears to diverge, interband coupling vanishes, and a local-moment state appears. It opens a new testing ground for theories of quantum criticality in heavy-fermion materials.

The role of postearthquake investigations in the National Earthquake Hazard Reduction Program

Data and basic knowledge gained from postearthquake investigation conducted under the auspices of the National Earthquake Hazard Reduction Program (NEHRP) have advanced the state - of - knowledge and state od practice in earthquake engineering. These advances have led to significant changes in public policy, focused research and accelerated the adoption of improved mitigation, preparedness, emergency response, and recovery measures in communities throughout the United Stated. Many countries throughout the world have benefited from investigations made during the past decade (AU)

Earthquake hazard and the role of insurance

The paper discusses some of the postulated economic impacts of earthquakes that have formed the supporting rationale for legislative proposals made to establish a national earthquake insurance program. Economic aspects of earthquakes and past earthquakes are discussed to see whether they collaborate these bases. The economic recovery from earthquakes is also discussed in order to identify appropriate policy areas under which earthquake insurance might be considered (AU)