Department of Applied Physics and Materials Science - Materials Science

News & Events

Highlights

Raising Temperature Changes an Element's Electronic "Topology"

10-27-16

Brent Fultz, Barbara and Stanley R. Rawn, Jr., Professor of Materials Science and Applied Physics, and colleagues have discovered a new way that heat tweaks the physical properties of a material. The potential value to engineers lies in the fact that it is much easier to raise the temperature of a material than it is to place it under the sort of pressure needed to force an electronic topological transition. [Caltech story]

Tags: APhMS research highlights Brent Fultz

New Breed of Optical Soliton Wave Discovered

09-06-16

Kerry Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics, and colleagues have discovered a new type of optical soliton wave that travels in the wake of other soliton waves, hitching a ride on and feeding off of the energy of the other wave. Solitons are localized waves that act like particles. Professor Vahala likens these newly discovered solitons to pilot fish, carnivorous tropical fish that swim next to a shark so they can pick up scraps from the shark's meals. And by swimming in the shark's wake, the pilot fish reduce the drag of water on their own body, so they can travel with less effort. [Caltech story]

Tags: APhMS research highlights Kerry Vahala

Smaller Chips May Depend on Vacuum Tube Technology

06-05-16

A recent New York Times article featured Caltech alumnus, Gordon Moore (PhD ’54), and the research of Professor Axel Scherer on ultrasmall vacuum tube as a candidate to replace the transistor. [Read the article]

Tags: APhMS EE research highlights CMS Gordon Moore Axel Scherer

Using Applied Physics to Explain How Accretion Disks Drive Astrophysical Jets

04-01-16

Paul M. Bellan, Professor of Applied Physics, has developed a new model explaining why astrophysical jets always originate from stars having accretion disks, the progenitors of planets. The relationship between jets and accretion disks has eluded scientists for many years and what happens to the angular momentum of accreting particles has also long been a mystery. Professor Bellan’s model explains how the disks power the jets as well as how angular momentum is removed from accreting material in the disks. The model involves peculiar inward spiraling trajectories of clumps of charged and neutral particles, and shows that the disk and jets together form an electric circuit where the disk is the battery and the jet is the load. [Read the Paper]

Tags: APhMS research highlights Paul Bellan

Seeking a Balanced Equation

03-21-16

Applied Physics graduate student Peter Hung, working with Professor Roukes, is one of the Caltech students featured in a recent E&S article. “In our lab, we shoot molecules of different sizes and shapes at really small mechanical resonators—tiny bridges almost 1,000 times smaller than the width of your hair—and use the change in the resonant frequency (how fast these bridges are vibrating) to reconstruct the shape and mass of the molecules that we’re shooting,” Hung explains. [E&S article]

Tags: APhMS research highlights Michael Roukes Peter Hung

Tiny Diatoms Boast Enormous Strength

02-08-16

Researchers in the lab of Julia R. Greer, Professor of Materials Science and Mechanics, have recently found that diatom shells have the highest specific strength—the strength at which a structure breaks with respect to its density—of any known biological material, including bone, antlers, and teeth. [Caltech story]

Tags: APhMS research highlights MedE MCE Julia Greer

Novel Calibration Tool Will Help Astronomers

01-27-16

Kerry Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics; Executive Officer for Applied Physics and Materials Science, and colleagues have developed a novel calibration tool, called a laser frequency comb, which could allow astronomers to take a major step in discovering and characterizing earthlike planets around other stars. The comb produces easily resolvable lines, without any need for filtering and is built from off-the-shelf components developed by the telecommunications industry. "We have demonstrated an alternative approach that is simple, reliable, and relatively inexpensive," says Professor Vahala. [Caltech story]

Tags: APhMS research highlights Kerry Vahala

Full Circle Physics

10-20-15

Dive into the thinking of several Institute for Quantum Information and Matter (IQIM) researchers including Oskar J. Painter, John G Braun Professor of Applied Physics and Fletcher Jones Foundation Co-Director of the Kavli Nanoscience Institute, to learn more about the frontiers of quantum science, the role IQIM plays in exploring that frontier, and the question oft thought but rarely spoken: Why should we care? [E&S article]

Tags: APhMS research highlights Oskar Painter

Inaugural Centers Announced for the Materials Genome Initiative

10-05-15

William A. Goddard III, Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics, will be the Caltech Principle Investigator for one of U.S. Department of Energy’s inaugural centers for the Materials Genome Initiative (MGI). The initiative was launched by the White House to “help businesses discover, develop, and deploy new materials twice as fast.” The three inaugural centers are receiving $8 million to “integrate theory and computation with experiment and provide the materials community with advanced tools and techniques in support of the MGI.” Professor Goddard and colleagues will be working on the Computational Synthesis of Materials Software Project with the goal of developing the next-generation of methods and software to predict and control materials processes at the level of electrons. [Learn more]

Tags: APhMS research highlights William Goddard

Atomic Fractals in Metallic Glasses

09-18-15

Julia R. Greer, Professor of Materials Science and Mechanics, and colleagues including graduate student David Chen have shown that metallic glasses has an atomic-level structure although it differs from the periodic lattices that characterize crystalline metals. "Our group has solved this paradox by showing that atoms are only arranged fractally up to a certain scale," Greer says. "Larger than that scale, clusters of atoms are packed randomly and tightly, making a fully dense material, just like a regular metal. So we can have something that is both fractal and fully dense." [Caltech story]

Tags: APhMS research highlights MedE MCE Julia Greer David Chen