In a letter to the Caltech community during National Postdoc Appreciation Week, the Caltech President emphasizes the role this key group plays at the Institute. He stated, “Caltech's mission of world-leading research and education depends crucially on our postdoctoral scholars. Although their time at Caltech may be short, they quickly become vital parts of the Institute's intellectual fabric.” [President’s Letter] [EAS Postdoc Resource Page]
Applied physics student Sunash Sharma, advised by Professor Stevan Nadj-Perge, is a recipient of the 2018 Henry Ford II Scholar Award. He has wide-ranging interests from biophysics to fluid mechanics to quantum computation. The Henry Ford II Scholar Award is funded under an endowment provided by the Ford Motor Company Fund. The award is made annually to engineering students with the best academic record at the end of the third year of undergraduate study.
Marco Bernardi, Assistant Professor of Applied Physics and Materials Science, has teamed up with physics colleague Professor David Hsieh, to offers new insight into a promising solar cell material called perovskites. "Despite being a relatively new technology, perovskite solar cells are now almost as efficient as solar cell materials that have been around for decades. But we still don't know why perovskite solar cells work so well," says Professor Bernardi, [Caltech story]
Professor Kerry J. Vahala and colleagues have developed a prototype of a miniature device that synthesizes frequencies on demand with about 1 Hertz accuracy. It combines a frequency comb developed at the National Institute of Standards and Technology (NIST) with a "fine-toothed" frequency comb developed at Caltech. To create the finely spaced comb teeth, the Caltech resonator must be about 100 times larger than the NIST device. Its larger size can potentially make this comb very power hungry. "Too much power in a small space can damage any electronics to which the resonator is connected," Professor Vahala says. "Also, in the future, these synthesizer devices could operate on battery power in smartphone-sized devices where they cannot draw much power." But the Caltech comb can generate specific frequencies with minimal amounts of power. [Caltech story]
Professor Harry A. Atwater, Jr. is an advisor to a multi-disciplinary $100-million project aimed at designing a spacecraft that can be launched to planets surrounding other stars and reach them within our lifetime. The Breakthrough Starshot Program has three big technical challenges: The first is to build the so-called photon engine, the laser that's capable of propelling the sail; the second is to design the sail itself; and the third is to design the payload, which will be a tiny spacecraft capable of taking images and spectral data and then beaming them back to the earth. Professor Atwater’s role is to help the program define pathways to making a viable lightsail that's compatible with the other objectives of the whole program. [Caltech story]
Most materials expand when heated. At temperatures below room temperature, silicon shows the opposite behavior, shrinking as it is heated. Even at room temperature the normal thermal expansion of silicon is rather small. A team led by Professor Brent Fultz wanted to know why, and found that the unusual property is the result of quantum effects coupled by the nonlinear forces between atoms in silicon. [Read the paper]
Brent Fultz, Barbara and Stanley R. Rawn, Jr., Professor of Materials Science and Applied Physics, has been named a 2018 Fellow of the Minerals, Metals, and Materials Society (TMS). Professor Fultz received the award for leadership in establishing the importance of vibrational entropy to the phase stability of alloys and for transformational advances in measurement techniques. This is a pinnacle award for the society and it recognizes outstanding contributions to the practice of metallurgy, materials science, and technology. [List of TMS fellows]
Marco Bernardi, Assistant Professor of Applied Physics and Materials Science, has been awarded the National Science Foundation's (NSF) Faculty Early Career Development (CAREER) Award for his 5-year project, “First-Principles Electron and Spin Dynamics in Materials with Spin-Orbit Coupling”. The CAREER program is NSF's most prestigious awards for junior faculty members. The level and 5-year duration of the awards are designed to enable awardees to develop careers as outstanding teacher-scholars. Awardees are chosen because they exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations. [Caltech story]
Marco Bernardi, Assistant Professor of Applied Physics and Materials Science, and his colleagues’ semiconductor research has shown that the coupling between electrons and thermal vibrations may be sapping energy from Light-emitting diodes—or LEDs. "Our work shows for the first time that the ever-present interaction between electrons with lattice vibrations can, by itself, explain why excited electrons can leak out of the active layer and account for inefficiencies in GaN LEDs," Professor Bernardi says. [Caltech story]
