James Hannon and Karsten Pohl were two of the University of Pennsylvania graduate students who moved to Tennessee in the winter of 1992. Jim is shown below with the high-resolution electron energy loss Spectrometer that he put together (writing all of the software). His thesis, which was accepted in 1994, is titled “The Structure and Dynamics of Beryllim Surfaces.” Two of the most referenced papers from the thesis are:

• Anomolous Interplanar Expansion at the (0001) Surface of Be, H. L. Davis, J. B. Hannon, K. B. Ray, and E. W. Plummer, Phys. Rev. Lett. 68, 2632 (1992)
  
• Phonon Dispersion at the Be(0001) Surface, J. B. Hannon, E. J. Mele, and E. W. Plummer, Phys. Rev. B 53, 2090 (1996).

After finishing his thesis Jim went as a Humboldt Fellow to work with Harald Ibach in Julich. He returned to the USA as a post-doctoral researcher at Sandia National Laboratory. In 1998 he joined the faculty at Carnegie Mellon and at present works at IBM research laboratory in Yorktown Heights.

Karsten Pohl came to the University of Pennsylvania with a diploma in physics from the Ludwig-Maximilians University in Munich, Germany. He completed his thesis titled “The Surfaces of Beryllium and their Interaction with Hydrogen,” in 1997. Two important papers from the thesis are:

• Anomalously Large Thermal Expansion at the (0001) Surface of Beryllium without Interlayer Anharmonicity, K. Pohl, J.-H. Cho, K. Terakura, M. Scheffler, and E. W. Plummer, Phys. Rev. Lett. 80, 2853 (1998).
  
• Structure of the H-induced vacancy reconstruction of the (0001) surface of beryllium, (K. Pohl, and E. W. Plummer), Phys. Rev. B 59, R5324 (1999).

After completing his thesis he became a post-doctoral researcher at Sandia Livermore. In 2000 he accepted a tenure track faculty position at the University of New Hampshire (http://www.physics.unh.edu/people/profiles_old/pohl.xml).