Assistant Professor This email address is being protected from spambots. You need JavaScript enabled to view it.
Campbell Hall 343
(205) 934-8031

Research and Teaching Interests: Quantum Mechanics, Atomic Physics, Plasma Physics, Laser Spectroscopy, Laser Cooling, Next Generation Frequency Standards, Nanotechnology, Atomic Sensors

Office Hours: By appointment only


  • B.S., Prairie View A&M University, Physics
  • Ph.D., Rice University, Physics


Dr. Simien studied physics and mathematics at Prairie View A&M University in Southeast Texas as an undergraduate. During those studies he worked on the BaBar Experiment at the Stanford Linear Accelerator Center, which was designed to study some of the most fundamental questions about the universe by exploring elementary particles using high energy physics techniques. 

As a David and Lucile Packard Scholar doctoral student at Rice University, he studied atomic physics, with a specific emphasis on applying laser cooling and trapping techniques to create strongly correlated plasmas, which are exotic systems useful for testing and advancing scientific understanding of plasmas. As a National Research Council Postdoctoral Fellow at the National Institute of Standards and Technology he performed precision laser spectroscopy to test quantum-electrodynamic calculations of many-body atomic systems.

You can also learn more about Dr. Simien's work through ResearchGate.


Research Interests

Dr. Simien’s current research emphasis is the use of laser spectroscopy and cooling and trapping techniques for the following:

  • to create and investigate the physics of strongly correlated matter,
  • to develop the next generation atomic clocks,
  • to test quantum-electrodynamic calculations,
  • to investigate the science and technology of high intensity discharge lamps for more lighting efficiency, and
  • to explore novel nanofabrication techniques using cold atoms respectively.
The following are the major research areas of the group.

 Spectroscopy, Collisional, and Laser Cooling and Trapping of Rare Earth Elements
This research area investigates rare earth elements as prospective candidates for next generation atomic clocks and for laser cooling. Atomic clocks have been instrumental in the advancement of science and technology in the twentieth century, leading to innovations such as global positioning, advance communications, and tests of fundamental particle physics. A next generation optical atomic clock would extend the capabilities of these systems and will enable a renaissance of timing applications such as enhanced security for data routing and communications, advance earth and space time-based navigation, geophysical surveying, testing Einstein’s Theory of General Relativity, and searches for variations in the fundamental constants of the universe.

Laser cooling is a technique for which the mechanical action of light is used to reduce the velocity of an atom in a gas. The use of lasers to cool atoms opened up new frontiers in physics ranging from the formation of new states of mater to enabling novel nanotechnologies. The extension of laser cooling to rare earth elements will enable the creation of novel ultracold atomic systems with unique properties and dynamics, and possibly provide for superior time and frequency standards.

Ultracold Neutral Plasmas
Ultracold neutral plasmas (UCNP), which are created from photo-ionizing laser cooled atoms in a Magneto-Optical Trap (MOT), stretch the boundaries of traditional plasma physics. These plasmas have electron kinetic energies in the 1-1000K range, and ion kinetic energies on the order of a few Kelvin. These exotic laboratory plasmas open up a new frontier in physics that cross-fertilizes plasma physics with modern atomic and condensed matter physics. They are highly controlled laboratory realizations of a strongly coupled two component plasma system, where the Coulomb interaction between nearest neighbors exceeds the thermal energy of the particle. These plasmas are extremely correlated and have unexplored phases with novel equilibrium and thermodynamic properties. Therefore studying these systems will better our understanding of low temperature strongly coupled plasma physics.

Recent Courses

  • Introduction to Quantum Mechanics
  • Scientific Communication

Select Publications

  • R. Brown, S. Wu, J.V. Porto, C.J. Sansonetti, C.E. Simien, J.D. Gillaspy, Joseph N. Tan, S.M. Brewer, “Light polarization and quantum interference effects in unresolvable atomic lines: with application to precision measurements of the 6,7Li D lines,” Physical Review A 87 (2013):032504.
  • C.J. Sansonetti, C.E. Simien, J.D. Gillaspy, Joseph N. Tan, S.M. Brewer, R. Brown, S. Wu, and J.V. Porto, “Absolute transition frequencies and quantum interference in a frequency comb based measurement of the 6,7Li D lines,” Physical Review Letters 107 (2011):023001.
  • C.E. Simien, S.M. Brewer, J.N. Tan, J.D. Gillaspy, and C. J. Sansonetti, “Measuring the D-lines of Li isotopes using an optical frequency comb,” Canadian Journal of Physics 89 (2010):1-5.

Academic Distinctions and Professional Societies

  • American Physical Society
  • National Society of Black Physicists
  • Association for the Advancement of Science