NEWS | Sept. 7, 2011

Dr. Michelle Johannes Receives 2011 Sigma Xi Young Investigator Award

By Daniel Parry

Dr. Michelle Johannes, a computational physicist at the Naval Research Laboratory Center for Computational Materials Science, receives this award for her innovative computational and theoretical work in the field of energy-related materials.

Dr. Johannes's computational research has contributed strongly to the understanding and improvement of materials properties, especially energy-related materials, by describing and clarifying a surprisingly diverse set of phenomena such as novel superconductivity, electrochemical performance in battery electrodes, fuel cell catalysis, charge density waves and magnetic interactions.

The computational work of Dr. Johannes in understanding the fundamental properties of materials has contributed strongly in a surprisingly wide number of fields, said Dr. Michael Mehl, head, NRL Center for Computational Materials Science. The impact of her work in her original field of novel superconductivity is indisputable, and has successfully transitioned to make significant contributions to areas of research as diverse as magnetism, charge density waves and battery electrode materials.

Dr. Johannes and collaborators predicted the symmetry of the superconducting state of the new Fe-based superconductors in the context of the nearby magnetic transition and Fermi surface nesting. These high profile works established Dr. Johannes as a leading theorist in the novel superconductivity field.

The role of Fermi surface nesting in superconductivity prompted Dr. Johannes to undertake work on Niobium Diselenide (NbSe2) where it was thought that Fermi nesting-driven charge density waves (CDWs) compete with superconductivity. This resulted in the important and general result that Fermi surface nesting alone cannot generate CDWs, but can generate superconductivity via spin fluctuations.

Michelle and her collaborators have essentially laid the foundation of the current understanding of the physics in iron-based superconductors, adds Dr. Mehl.

Using advanced computational methods to develop theoretical models of materials vital to energy production and preservation, Dr. Johannes examines materials at the atomic level allowing her to create precise models and subsequent better, more optimal materials.

In order to better conserve and efficiently use energy, we need a basic understanding of the materials that generate and store it, says Dr. Johannes. My calculations help to provide this understanding and make predictions of how to improve these important materials. A critical step as she describes, Because energy is one of the primary concerns of society, both military and civilian.

Dr. Johannes received her doctorate in physics in 2003 from the University of California at Davis and began her career studying novel superconductivity in the wake of the discovery of the cuprates - the canonical magnetically driven high temperature superconductors.

Continuing to lead theory development in her field, Dr. Johannes is leading a new Nanoscience Institute (NSI) project at NRL to understand how nanoscale morphology can activate high-energy electrode materials, a project that is proving very promising in producing the highest-ever reported lithium capacity in a non-aligned nanowire anode.