Sergio Ulloa is a condensed matter theorist, interested especially in
collective effects and in how small size affects the physical
properties of different materials. He continues to be surprised by
the fact that electrons inside a solid behave quite differently than
electrons elsewhere. As one tries to push one electron forward in a
solid, the rest of them appear to tag along. Sometimes the result is
not just a cloud of electrons moving, but a quasiparticle that
exhibits completely different properties of mass, spin, and
charge. This fascinating behavior comes about because electrons (as
well as other particles) interact strongly with one another and obey
quantum mechanics. Thanks to recent advances in experiments, this
behavior can be tested under new conditions of size, so that one can
investigate the system one quasiparticle at a time and extract a
better understanding of nature at the nanoscale. Sergio tries to
understand this behavior under different conditions, and compare his
theoretical predictions aided by numerical simulations with
experiments performed at Ohio University and elsewhere.
Ulloa tells his students that learning physics is a bit like learning a foreign language, having experienced it himself. One needs to learn the grammar (math), vocabulary (definitions), and then use one's imagination to put new sentences together (solve problems). Learning requires practice and application. The ensuing success allows one to see into and communicate with a new world! It is very exciting!
Ulloa was elected a Fellow of the American Physical Society
(nominated under the Division of International Physics) in 2007 ``For
his contributions to the theory of transport and optical properties of
low-dimensional semiconductor systems and complex molecules, and his
many contributions to international physics as organizer of schools,
workshops, and conferences, in particular in Latin America''.
When he is not working, he likes to be with his family, travel, read, and work on international and Hispanic issues in physics. And he enjoys taking care of his beautiful baby girl, Julia Mia.
