I was born in St. Louis, Missouri in 1968, attended a Jesuit high school (St. Louis University High School,) and was active in electronics, early 8-bit personal computers, amateur astronomy, telescope building, and the Boy Scouts, earning the rank of Eagle Scout. I studied physics at the University of Chicago (1986-90,) and worked with Prof. Albert Libchaber and his research group for my thesis project. We demonstrated crystal facets in 2D (Nature 1990): crystallization in 2D was thought to be impossible by the Mermin-Wagner theorem.
In 1990 I began my PhD in physics at the University of California Berkeley where I studied ultra-low temperature physics with Prof. Richard Packard. My PhD thesis project (PhD 1996) investigated the nucleation of quantized vortices in superfluid helium (PRL 2005), and demonstrated a superfluid quantum interference device which was able to detect the Earth's rotation (Nature 1997). Realization of this superfluid device, an analogue of the superconducting rf-SQUID, had been attempted numerous times in various laboratories around the world since 1970.
In 1996, I joined Prof. Michael Roukes' research group at the California Institute of Technology as the Sherman Fairchild Distinguished Post Doctoral Scholar. There I probed energy transport through nanoscale mechanical structures and made the first observation of the quantum of thermal conductance (Nature 2000), a result which Joseph Pendry had predicted in 1983. The micrograph of the nanostructure created for this work is part of the permanent collection at the MOMA (New York.)
In 2000, I joined the National Security Agency (NSA), 18 months before the 9-11 attack, as a member of the effort on low temperature quantum devices for application to quantum computing. I formed and led a research group focused primarily on the investigation of quantum effects in nano-electro-mechanical devices and the applications of nanotechnology to atomic and quantum optics experiments. These experiments demonstrated measurements of motion very near the Heisenberg Uncertainty Principle (Science 2004), measurements showing the closest approach to the quantum ground state for a mechanical oscillator (Nature 2006). Our measurements showed that subtle quantum back-action effects with both electrical (Nature 2006), and optical forces (Nature 2006) which can be utilized to cool mechanical structures to the quantum ground state. Furthermore, for the first time, the random motion of the object measured was limited by the shot-noise of the particles used for measurement. During this period, together with colleagues we began to formulate schemes to produce mechanical superposition states using quantum electronic devices, superconducting qubits (PRL 2002), and laid the foundation for what is now called "quantum optomechanics," (Physics Today 2012.) Beyond fundamental research, the period at the NSA allowed me to develop my interest in areas related to national security and the US Intelligence Community, especially during the post 9-11 period.
At the intersection between nanotechnology, atomic physics, and quantum engineering we demonstrated the first microfabricated ion trap for applications to quantum computation (Nature Phys. 2005.) Together with Prof. Kamil Ekinci, we realized a radio frequency scanning tunneling microscope (RF-STM) which demonstrated atomic resolution imaging of surfaces at video rates, atomic resolution local thermometry using shot noise, and detection of motion of radio frequency nanomechanical structures (Nature 2007).
I joined the faculty of Cornell University Department of Physics in April of 2006, and then Caltech in January 2009. I constructed an ultra-low temperature laboratory to further probe the quantum limits of measurement. In collaboration with my first PhD student Prof. Matt LaHaye, and my post doc advisor Prof. Michael Roukes (Caltech), we produced the first measurements of a superconducting qubit coupled to a mechanical resonator (Nature 2009). This system is expected to be very rich and to lead to the formation of a quantum superposition of the mechanical device, a method to perform quantum non-demolition measurements of mechanical number states (PRB 2003) and quantum interference fringes of a mechanical element (NATO 2003).
My research group at Caltech demonstrated quantum non-demolition measurements of motion and the mechanical sensing of microwave frequency photon shot noise (Science 2014). We then utilized these techniques to create and measure quantum squeezing of mechanical motion (Science 2015, PRL 2016). We have also pioneered the investigation of thermal transport through single micron-size flakes of graphene which demonstrates very weak coupling between electrons and phonons and extremely low electronic heat capacity at low temperatures (PRX 2012, PRX 2013.)
Currently, I have been attempting to focus my efforts on utilizing the unique quantum properties of superfluid helium-4 to realize quantum devices such as qubits and matter-wave interferometers, and ultra-sensitive detection of forces and accelerations. We have coupled a gram-scale acoustic resonator of helium to a very low dissipation superconducting microwave cavity which realized the first superfluid optomechanical system (New J. Phys. 2014) and have observed extraordinary acoustic quality factors in excess of 100 million (JLTP 2017). We expect this system to demonstrate the lowest acoustic loss of any material and to find application in the detection of narrow band gravitational wave from pulsars (New J. Phys. 2018) and the exploration of quantum physics at extremely small length scales. Furthermore, we are exploring the transport of liquid helium through new 2D nanoporous materials (created by Prof. Ben King at Univ. of Nevada Reno) which is expected to demonstrate the Josephson effect far below the superfluid transition temperature and be the basis of ultra-sensitive matter-wave interference gyroscopes and superfluid quantum information devices.
Although the opportunities for breakthroughs with superfluid quantum devices is clear, it is very challenging to stimulate interest to fund this work. I would have never imagined that it would be impossible to find funding at the National Science Foundation (DMR) for this work.
Outside the laboratory, I have participated in a broad range of activities where scientists can play an important role. I was a member of the Young Global Leaders which is a sub-group of the World Economic Forum and have participated in the annual meeting at Davos Switzerland (2005, 2007, 2008). I have lectured at the Museum of Modern Art, and participated in a Fred Friendly panel discussion for public television (PBS) on the issue of nanotechnology, privacy, and security, and contributed to Entertainment Gathering EG2-2007.
I enjoy hiking, backpacking (California, Alaska, Wyoming, New Mexico, Arizona) landscape photography, and flying gliders cross country. I currently fly a DG303 and my current personal records are: altitude: 27,300'(gps), distance: 443 mi, time: 8 hrs, satisfying SSA Silver, Gold, and Diamond badges, Symons Wave Memorial One-Lennie. My goal for the 2020 season is a 750km declared flight in the Owens Valley and a flight above 35,000' (Double-Lennie).
Tracks of longer soaring flights.
For some examples of the photographs:
For ultra-low noise pre-amplifiers, please visit:
274 Watson Laboratory
California Institute of Technology
1200 E. California Blvd.
Pasadena, CA 91125 USA