Amy Liu

Amy Liu's picture
Amy Liu
Professor

554 Reiss Science Building
Telephone: (202) 687-6583

E-mail: liu [at] physics [dot] georgetown [dot] edu

Website: http://physics.georgetown.edu/~liu

Amy Liu received her A.B. in physics from Cornell University in 1985 and her Ph.D. in physics from U.C. Berkeley in 1991. After post-doctoral work at the Naval Research Laboratory and the NEC Research Laboratory, she joined the physics department at Georgetown.

Her primary research interests include the electronic, structural, and vibrational properties of crystals, interfaces, and clusters; electronic instabilities such as superconductivity and charge density waves; anharmonicity and thermal properties of materials. She is also interested in simulations of signaling processes in cells.

Current Research

Ab initio studies of materials

Computational quantum-mechanical approaches to the electronic structure of matter have proven to be useful tools for understanding and predicting the properties of materials. In recent work, we have used these tools to investigate

  • electron-phonon coupling in layered superconductors, such as MgB2, intercalated graphite, and the hypothetical LiB. These materials share the common structural feature of graphene-like atomic layers, but calculations show that they take advantage of different mechanisms for achieving strong coupling between electrons and phonons.
  • stability and bonding in boron cluster materials. Recently, large cage-like structures, analogous to the carbon fullerenes, have been predicted for boron clusters. We are interested in the stability of these boron clusters, both in the gas phase as well as in condensed forms
  • competing instabilities in charge density wave materials. Charge density waves and superconductivity both result from electronic instabilities that lead to collective behavior of electrons in materials. We are studying materials where they coexist to better understand the relationship between these two phenomena: are they in competition, or do they cooperate with each other?

Calcium dynamics in cells

Cells make use of a variety of mechanisms to release and remove Ca from the cytosol, which allows the formation of complex patterns that can encode specific signaling functions. Using a reaction-diffusion model, we are studying calcium dynamics, focusing on effects of geometry and heterogeneity in multi-compartment cells.

Selected Publications

  1. A. Y. Liu, R. R. Zope, and M. R. Pederson, Structural and bonding properties of bcc-based B80 solids, Phys. Rev. B 78, 155422 (2008).
  2. A. Y. Liu and I. I. Mazin, Combining the advantages of superconducting MgB2 and CaC6 in one material: Suggestions from first-principles calculations, Phys. Rev. B 75, 064510 (2007).
  3. I. Schnell, I. I. Mazin, and A. Y. Liu, Unconventional superconducting pairing symmetry induced by phonons, Phys. Rev. B 74, 184503 (2006).