Most geometrical modelers for 3D objects use 2D interaction techniques and make little use of 3D display techniques. This interaction style forces the user to decompose 3D design operations into sequences of 2D interface operations, and there is an extra cognitive load of interpreting the 2D displays as a 3D object. While this may be acceptable for drafting applications, it has a significant ne...

Topological energy bands have important geometrical properties described by the Berry curvature. We show that the Berry curvature changes the hydrodynamic equations of motion for a trapped Bose-Einstein condensate, and causes significant modifications to the collective mode frequencies. We illustrate our results for the case of two-dimensional Rashba spin-orbit coupling in a Zeeman field. Using...

The origin of ferroelectricity in KH2PO4 (KDP) is studied by first-principles electronic structure calculations. In the low-temperature phase, the collective off-center ordering of the protons is accompanied by an electronic charge delocalization from the near and localization at the far oxygen within the O-H· · ·O bonds. Electrostatic forces, then, push the K+ ions towards off-center positions...