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   COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
                   School of Computational Sciences
                           (CSI 898-Sec 001)
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          Superconductivity of Alkali Metals under High Pressure

                            Lei Shi
  School of Computational Sciences, George Mason University, Fairfax, VA

     We calculated the superconductivity properties of alkali metals
under high pressure using the results of band theory and the rigid-muffin-tin
theory of Gaspari and Gyorffy. Our results suggest that at high pressures
Lithium, Potassium, Rubidium and Cesium are superconductors with
transition temperatures approaching 5-20 K. Our calculations also suggest that
Sodium is not a superconductor under high pressure even if compressed to
less than half of its equilibrium volume. We found that the compression of the
lattice strengthens the electron-phonon coupling through a delicately balanced
increase of both the electronic and phononic components of this coupling. This
increase of the electron-phonon coupling in Li is due to an enhancement of the
s-p channel of the interaction, while in the heavier elements the p-d
channel is the dominant component.

                        February 6, 4:30 pm
               Room 206, Science & Tech. I, Fairfax Campus

Refreshments will be served at 4:15 PM.
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Find the schedule at http://www.scs.gmu.edu/lcdm/seminar/schedule.html
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