In the lab

My work in the physics department at Montana State University involves the magnetic and electronic structure characterization of nanoparticles. A detailed description of this project can be found on our group's page at this location. Another description of my research can be found in my resume (link below). In a sentence, we study the emergent properties that arise as we approach the 0-dimensional limit. Our systems are metal oxide spherical particles with diameters between 4 and 24 nm. Metal = {Fe, Co, Mn, Eu, Zn, Ti, and others}. By 0-dimensional we mean that the particles are single domain magnets and many -> most of the unit cells are on the surface of the particle. The measurement techniques we employ are magnetometry (hysteresis loops), magnetic susceptibility, electron microscopy, and x-ray absorption. The x-ray experiments are conducted at synchrotrons (NSLS and ALS) and the other measurements are performed on campus. Please see the link indicated above for more details.

As I shift into my new role as the group 'theorist' I will be getting my hands dirty less often and be doing many more calculations, both analytical and computational. Our magnetometry data presents many strange results that appear to require new models to explain. This is largely due to the fact that at low temperatures the systems can get stuck in non-equilibrium configurations (hence, hysteresis) and equilibrium thermodynamic arguements no longer apply. More sophisticated computational modeling (MO, DFT, LDA) will seek to shed light on the electronic structure changes at small radii. However, this shift in focus has not been apparent to those who have spotted me in the chemistry building, pipette in hand, making samples.

Things I think about outside the lab

While general relativity has stood up well to every test conducted thus far, such experiments, or observations, are often very difficult and expensive to perform. To my knowledge, LISA is not yet budgeted, the recently launched Gravity Probe B was 40 years in the making, and no observation of Hawking radiation has been made thus far. Nature, in Her wonderful way, may allow us to study intriguing gravitational phenomenon with table-top condensed matter systems.

The basic idea is to write an effective metric for the propagation of a given particle or quasiparticle. Examples would be light traveling in an optically slow medium, quasiparticle excitations in superfluid He3, sound waves in a moving medium, etc. Such systems should allow one to simulate event horizons, Hawking radiation, black hole evaporation, possibly frame dragging, and other 'solely' gravitational effects. This idea is not a new one, but, in fact, has been around since Gordon first posed it in 1923. The last decade or two has experienced an explosion of theoretical contributions to this area, but I am unaware of any satisfactory experimental efforts. A nice summary of the field may be found here.

Although non-equilibrium thermodynamics makes an appearance in many standard statistical mechanics texts it appears not to be a well understood area of physics. In fact, the problem is less that the subject is not well understood, but more that it is not well defined. A particularly intriguing question is whether thermodynamic quantities, such as temperature and entropy, are Lorentz invariants. That is, how do these quantities transform in the special relativistic framework. This question has an equally interesting, and older, history than the previous topic. The question of the relativistic transformation of temperature was first discussed by Einstein in 1907 (just two years after his debut of relativity). Believing entropy to be invariant, Einstein concluded that T' = T/gamma (cooling). This result remained unchallanged until 1963 when Ott proposed, oppositely, that T' = gamma*T (warming). In 1980 Landsberg presented a scheme by which the transformation relation could actually be measured. Interestingly, in 1996, Landsberg reported that a unique transformation was an impossibility.

Why has this field experience such confusion for so long? In my opinion, and that of others, it is due to the fact that the standard definitions of temperature are simply inappropriate when systems are out of equilibrium. A system considered to be in equilibrium by one observer will not necessarily be seen to be in equilibrium by another observer. Thus, a more general definition of temperature (and other thermodynamic quantities) is required to settle this matter. Interestingly, owing to the freedom of these definitions the answer cannot be determined by measurement, but must, almost arbitrarily, be chosen.

For a very thorough summary of this fascinating conundrum see this review article (warning, 87 pages).

Lie groups, QED/QFT, and MO calculations.

I think I am destined to become a "mathematical physicist" because I am completely unable to pick one subject and stick with it.

Things I do outside the lab

I consider Bozeman to be something of a strange attractor: people never seem to be able to escape its grasp, but their orbits may be quite bizarre. Montanans consider their state to be the last best place and I have to say it has been a fantastic place to live. Outdoor recreation abounds year round: skiing, backpacking, fishing, biking, etc. Nearby Yellowstone and Glacier National Parks are simply spectactular. Check out the goodies.

I have learned that as a poor graduate student it is very valuable to have friends who live in interesting places. Having many friends who lead more interesting lives than my own has allowed me to travel to Mali, France, and Peru.