Department of Applied Physics and Materials Science - Applied Physics

News & Events

Highlights

How Iron Feels the Heat

02-13-15

Brent Fultz, Barbara and Stanley R. Rawn, Jr., Professor of Materials Science and Applied Physics, and colleagues’ recent work provides evidence for how iron's magnetism plays a role in its curious properties—an understanding that could help researchers develop better and stronger steel. With a better computational model for the thermodynamics of iron at different temperatures—one that takes into account the effects of both magnetism and atomic vibrations—metallurgists will now be able to more accurately predict the thermodynamic properties of iron alloys as they alter their recipes. [Caltech story]

Tags: APhMS research highlights Brent Fultz

New Technique Could Harvest More of the Sun's Energy

11-26-14

Harry A. Atwater, Jr., Howard Hughes Professor of Applied Physics and Materials Science as well as Director of the Resnick Sustainability Institute, and colleagues have created a new technique to harness the lost energy from solar panels. “Silicon absorbs only a certain fraction of the spectrum, and it's transparent to the rest. If I put a photovoltaic module on my roof, the silicon absorbs that portion of the spectrum, and some of that light gets converted into power. But the rest of it ends up just heating up my roof," explains Professor Atwater. Now they have found a way to absorb and make use of these infrared waves with a structure composed not of silicon, but entirely of metal. [Caltech story]

Tags: APhMS energy research highlights Harry Atwater

Heat Transfer Sets the Noise Floor for Ultrasensitive Electronics

11-10-14

Austin Minnich, Assistant Professor of Mechanical Engineering and Applied Physics, and colleagues have identified a source of electronic noise that could affect the functioning of instruments operating at very low temperatures, such as devices used in radio telescopes and advanced physics experiments. The team's findings also suggest that it may be possible to develop engineering strategies to make phonon heat transfer more efficient at low temperatures. For example, one possibility might be to change the design of transistors so that phonon generation takes place over a broader volume. "If you can make the phonon generation more spread out, then in principle you could reduce the temperature rise that occurs," Professor Minnich says. "We don't know what the precise strategy will be yet, but now we know the direction we should be going. That's an improvement." [Caltech release]

Tags: APhMS research highlights MCE Austin Minnich

Making Hotter Engines and Lasting Artwork

11-07-14

Katherine Faber, Simon Ramo Professor of Materials Science, studies the reasons why brittle ceramics fracture—and how these materials can be made stronger and tougher in the future. Her research interests have also been applied to sustainability and the arts. [Interview with Professor Faber] [ENGenious article]

Tags: APhMS research highlights Katherine Faber

Inside the Caltech Laboratories of Professors Atwater and Arnold

10-17-14

The creators of the Austrian TV documentary TM Wissen (TM Knowledge) go inside the laboratories of Professors Harry A. Atwater, Jr. and Frances H. Arnold to learn more about their research at Caltech.

Tags: APhMS energy research highlights Harry Atwater

Ceramics Don't Have To Be Brittle

09-11-14

Julia R. Greer, Professor of Materials Science and Mechanics, and her colleagues are on the path to developing materials that possess unheard-of combinations of properties. "Ceramics have always been thought to be heavy and brittle," says Professor Greer. "We're showing that in fact, they don't have to be either. This very clearly demonstrates that if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO to construct larger materials, you can obtain nearly any set of properties you want. You can create materials by design." [Caltech Release]

Tags: APhMS research highlights MCE Julia Greer

'Comb on a Chip' Powers New Atomic Clock Design

07-22-14

Scott Diddams who was a 2012 Caltech Moore Distinguished Scholar and is a Project Lead at National Institute of Standards and Technology (NIST) and colleagues including Professor Kerry Vahala have demonstrated a new design for an atomic clock that is based on a chip-scale frequency comb, or a microcomb. The microcomb clock is the first demonstration of all-optical control of the microcomb, and its accurate conversion of optical frequencies to lower microwave frequencies. Caltech researchers made the 2-millimeter-wide silica disk that generates the frequency comb for the new clock. [NIST Press Release] [Learn More]

Tags: APhMS research highlights Kerry Vahala IST Scott Diddams

Future Electronics May Depend on Lasers, Not Quartz

07-18-14

Kerry Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics as well as the Executive Officer for APhMS, and colleagues have developed a method to stabilize microwave signals in the range of gigahertz, or billions of cycles per second—using a pair of laser beams as the reference, in lieu of a quartz crystal. "There are always tradeoffs between the highest performance, the smallest size, and the best ease of integration. But even in this first demonstration, these optical oscillators have many advantages; they are on par with, and in some cases even better than, what is available with widespread electronic technology," Vahala says. [Caltech Release]

Tags: APhMS research highlights Kerry Vahala IST

Tricking the Uncertainty Principle

05-15-14

Keith Schwab, Professor of Applied Physics and the Fletcher Jones Foundation Co-Director of the Kavli Nanoscience Institute, and colleagues have found a way to make measurements that go beyond the limits imposed by quantum physics. "Our mechanical device is a tiny square of aluminum—only 40 microns long, or about the diameter of a hair. We think of quantum mechanics as a good description for the behaviors of atoms and electrons and protons and all of that, but normally you don't think of these sorts of quantum effects manifesting themselves on somewhat macroscopic objects," Schwab says. "This is a physical manifestation of the uncertainty principle, seen in single photons impacting a somewhat macroscopic thing." [Caltech Release]

Tags: APhMS research highlights Keith Schwab

Professor Greer Named One of Most Creative People in 2014

05-13-14

Julia R. Greer, Professor of Materials Science and Mechanics, has been named one of Fast Company's Most Creative People in 2014. "What if you could fabricate nanotrusses--materials made up of tiny, intricate geometric structures linked together--in a way that might resemble, say, the webwork of the Eiffel Tower?" describes Professor Greer. [Fast Company release] [research highlight]

Tags: APhMS honors research highlights Julia Greer