Materials Science Research Lecture

***Refreshments at 3:45pm in Noyes lobby

Abstract:
Superfluid helium-4 (sHe-4) is a remarkable quantum material: a liquid quantum condensate which appears at ~2K, can move without friction, demonstrates quantum phase coherence and quantized motion around macroscopic loops, and is available in large, pure quantities. I will provide an introduction to sHe-4, and then describe how to utilize its unique properties to create ultra-sensitive detectors of acceleration and rotation. I will discuss our experiments which demonstrated acoustic resonances with quality factor exceeding 10^8, and our current work to realize a Josephson junction for sHe-4 using a novel 2D nanoporous materials. Estimates of the sensitivities of these devices suggest they should be capable of detecting General Relativistic effects such as narrow-band gravitational wave from nearby pulsars, the twisting of space-time due to the rotating Earth, and the daily fluctuations in the Earth's rotation.

More about the Speaker:

Keith grew up in Missouri and received a BA in physics from the Univ of Chicago in 1990, and a PhD in physics from UC Berkeley in 1996. He was the Sherman Fairchild Distinguished Postdoctoral Scholar with Michael Roukes at Caltech from 1996-2000, where they demonstrated the quantum of thermal conductance. From 2000-2006 he lead a research group at the National Security Agency to explore quantum effects in mechanical devices. From 2006 to 2009 he was a professor at Cornell in the Dept. of Physics (too cold) and then moved to Caltech in 2009 and joined Applied Physics (too hot).