My research focuses on the non-equilibrium statistical physics of atmospheres and oceans for the purpose of understanding climate and climate change.  Strongly-correlated quantum many-body systems such as Mott insulators, quantum spin-liquids, and actinide compounds are another area of longstanding interest.  Brainstorming new ways to harvest solar energy, and understanding the solar cycle, are new topics that I'm exploring.  

The basic laws of quantum and statistical physics were discovered many decades ago, yet we continue to be amazed by the rich variety of behaviors and phases that emerge from these laws. Experiments on several classes of layered systems, on transport through nanostructures, and on nanoscale aqueous actinide complexes, call for a deeper theoretical understanding of strongly correlated electronic systems. The statistics of dynamical systems such as turbulent flows also require the accurate treatment of strong many-body correlations. I work with systematic analytical and numerical methods to establish phase diagrams, to study charge-transfer at surfaces and in aqueous environments, and to describe statistically nonlinear systems driven out of equilibrium. Attaining a better understanding of this physics is of both fundamental and practical import.

On intellectual grounds, my research pushes the boundaries of what can be done to ascertain emergent properties of strongly correlated systems. It bears on 6 of the 125 outstanding scientific questions recently identified by Science Magazine: (1) Is there a unified theory explaining all correlated electron systems? (2) What is the pairing mechanism behind high-temperature superconductivity? (3) What is the structure of water? (4) Can we develop a general theory of the dynamics of turbulent flows and the motion of granular materials? (5) Will mathematicians unleash the power of the Navier-Stokes equations? And (6) how hot will the greenhouse world be?

“Understanding high-level nuclear waste with strong electronic correlations,” Na- tional Academy of Sciences Keck Futures Initiative (NAKFI ANT7), $75,000, 5/1/2014 – 4/30/2016. 

National Science Foundation: “Strong Correlations in Environmental Condensed Matter,” NSF DMR-1306806, $275,000, 9/1/2013 through 8/31/2016. 

National Science Foundation: “Collaborative Research: Type 1 – LOI02170139: Direct Statistical Approaches to Large-Scale Dynamics, Low Cloud Dynamics, and their Interaction,” NSF, 5/1/11 – 4/30/15, $436,471.

[Grants prior to this are not listed.]

NSF American Competitiveness and Innovation Fellow (2008 -- 2011). Citation: "For his transformational interdisciplinary research harnessing the methods of theoretical condensed matter physics to attack climate modeling and the exceptional interdisciplinary educational opportunities that derive for the mentoring of his students."

Fellow of the American Physical Society (APS)

APS Outstanding Referee (2010)

National Science Foundation Creativity Extension (2008 -- 2011)

National Science Foundation Creativity Extension (2001 -- 2002)

Gordon Godfrey Fellow, University of New South Wales, Australia (2000)

Alfred P. Sloan Fellow (1994 -- 1998)

National Science Foundation Young Investigator (1993 -- 1998)

Fellow and lifetime member of the American Physical Society.

Member of the American Geophysical Union.

Physics lies at the foundation of the quantitative sciences, and I firmly believe that physics – not just the particular facts of physics, but more importantly the ways in which physicists approach problem solving – provides unsurpassed training for students concentrating in a wide range of disciplines. I had the good fortune to attend Richard Feynman's famous "Physics X" course during my time as an undergraduate at Caltech in the early 1980's. Feynman showed us that fascinating physics lurks behind everything, and that it is a delight to reveal it to others.

There is a well-defined core to the physics curriculum, and any serious university must teach this core. I have taught the full range of physics courses at Brown University: freshman physics for concentrators, pre-med physics, introductory astronomy with nighttime laboratories for science majors, sophomore electricity and magnetism, an undergraduate seminar in quantum computation, and graduate courses in quantum mechanics, advanced statistical mechanics and quantum many-body theory. I have employed the latest approaches and technology by developing new lecture demonstrations of quantum physics such as single-photon interference, by making extensive use of the web, and by applying the "Just in Time" Teaching method. However, the single most important factor in good teaching, I'm convinced, is the ability to see the world as fresh and new even as one teaches familiar material. A teacher who embodies this spirit will by example convey to students a sense of the enjoyment and excitement that comes from the discovery of new, and often surprising, things about the world.

At the boundaries of the physics curriculum lie several multidisciplinary fields of great current interest: Biological physics, nanoscience, and environmental science. Environmental physics classes have been taught elsewhere, but generally these have been based on the notion that physics presents us with a fixed set of tools that can then be applied to various environmental problems. In a new freshman seminar that I have developed at Brown, entitled Introduction to Environmental Physics: The Quantum Mechanics of Global Warming (PHYS0110/0120), I turn this logic around to suggest that complex environmental questions can spur further development of physical ideas.

Of course there is a whole other side to teaching: Training undergraduate and graduate students to carry out research. It requires intense individual attention from the advisor, and the results are uniquely satisfying. Much of my research is done with graduate students. It is wonderful to see these students mature into independent researchers who then go on to make significant contributions to theoretical physics. On the other hand undergraduates are more adventurous than graduate students. I have found that supervising senior thesis projects is a good way to explore new ideas because undergraduate students are willing to risk challenging conventional thinking.

My former undergraduate senior thesis students (6 women and 6 men) have continued their study of physics in graduate school. Three of my former graduate students have faculty positions, as have three of my former postdocs. I am committed to educating a diverse next generation of physicists.