Events

Spintronics explores the physics of interplay between spin and charge in condensed matter. It is one of the most active areas of magnetism. In particular, electrical manipulation of spin and magnetization in nanostructures allows us not only to study the interplay but can also be utilized to reverse magnetization direction, which is of great importance to nanoelectronics. In my lecture, I describe the nanoelectronics side and the science side of spintronics by discussing two topics that delineate the significance and technological importance of such spin manipulation in condensed matter.

The geometry of hyperbolas is the key to understanding special relativity.
The Lorentz transformations of special relativity are just hyperbolic
rotations, yet this point of view has all but disappeared from the standard
physics textbooks. This approach replaces the ubiquitous $\gamma$ symbol of
most standard treatments by the appropriate hyperbolic trigonometric
functions. In most cases, this simplifies the resulting formulas, while
emphasizing their geometric content.

Low cost and flexible integrated circuits will enable many new applications for our daily life. Amorphous silicon (a-Si) is the current material of choice for low-cost thin film transistors (TFTs) that are widely used as switching devices in active-matrix liquid-crystal displays. Organic (molecular crystals or polymeric) semiconductors with the advantages of flexibility and compatibility with solution-based low-cost processes (e.g. spin coating and ink jet printing) and plastic substrates are major candidates.

This work demonstrates some novel procedures for joining multiple solutions of the Einstein field equation in a way which creates a new analytical tool for studying them. Joining known solutions along shells ensures that we have solutions off the boundary. In 1985 Dray and 't Hooft showed how to use use spherically symmetric shells of massless matter to join spacetime regions with Schwarzschild geometry. We demonstrate here how to use these solutions to draw information-rich Penrose diagrams usable for investigating the characteristics of the solutions.