Student performs photolithography in our clean room

When a large number of atoms condense into a fluid or solid, behaviors emerge that are only indirectly related to the physics of the individual atoms. Superconductivity is one such an emergent behavior, which could not be anticipated from even a detailed study of an isolated atom. The goal of condensed matter physics is not only to measure and explain such emergent phenomena, but also to manipulate these properties to produce the novel effects we desire. This allows us to both investigate fundamental physics and to develop commercially important applications.

A student in condensed matter physics must have a thorough understanding of both the microscopic quantum mechanics that underlies the system and the classical macroscopic theories of mechanics, electromagnetism, and statistical mechanics that describe its large scale behavior. This broad background enables students to go on to careers in academia, government labs, and industry.

The condensed matter group encompasses semiconductor physics, soft-matter physics, and nanophysics. A major focus of our group is the experimental and theoretical study of highly confined electron systems in artificially structured semiconductors and other low dimensional materials.

We cover all aspects of these systems from fundamental theory to device fabrication. This group operates as part of the Center for Semiconductor Physics in Nanostructures (C-SPIN) one of the National Science Foundation's few Materials Research, Science and Engineering Centers. C-SPIN is a multi-million dollar, interdisciplinary research collaboration between scientists at the University of Oklahoma and the University of Arkansas. We have theoretical and experimental efforts in nano-scale semiconductor devices, spin transport in semiconductors and high-speed transistors. In addition to semiconductor studies, the group also has research efforts in high-efficiency photovoltaics, graphene, self-assembled monolayers, molecular plasmonics, nanoparticles, and lithium ion conducting polymers. Some of this work is performed in conjunction with researchers in the Departments of Chemistry and Biochemistry, Electrical & Computer Engineering, and Chemical, Biological, & Materials Engineering.

	Trenches etched by Prof. Johnson in GaAs using an Ar+ beam with an anodized aluminum oxide (AAO) mask. Note this technique can be done remotely in vacuo, thus it is fully compatible with MBE. This is an example of a "top-down" fabrication method.
	A flat gold nanoparticle grown by Prof. Bumm in solution, imaged by an electron microscope. The symmetric structure of the particle arises spontaneously from the local surface energies during growth. This is an example of a "bottom-up" method.

The majority of our experimental research takes place in the department's state-of-the-art laboratories.

Our well equipped facilities include: a dual-chamber molecular beam epitaxy (MBE) system for the growth of III-V and IV-VI semiconductors; several scanning tunneling and atomic force microscopes for high resolution imaging and patterning of atomic surfaces; a cleanroom for optical lithography and semiconductor processing; a thin-film laboratory for routine vapor deposition; low temperature (<20 mK) and high magnetic field (15 T) facilities for optical and electrical studies; optical microscopes for single nanoparticle spectroscopy; a grazing angle infrared spectrometer for molecular spectroscopy of monolayers; full characterization techniques for solar cells analysis including a class-A solar simulator, an external quantum efficiency system with capacitance-voltage analysis equipment; and picosecond pulsed laser systems for our polymer studies. Scanning electron and transmission electron microscopes are available in the Samuel Roberts Noble Electron Microscopy Laboratory and are routinely used by our students for their research.

The condensed matter theory group is interested in many areas of research including new quantum phases in strongly correlated systems, quantum criticality and transport in semiconductor and carbon nanoscale systems.

The faculty in condensed matter physics share appointments in the engineering physics program. The engineering physicist provides the link between the pure scientist and the engineer by applying fundamental scientific theories to the solution of technological problems. As the miniaturization of transistors, lasers, and memory elements continues, an understanding of their operation increasingly requires knowledge of the underlying physics.