Hybrid density functional band structure calculations on the cuprate superconductors

COMP 89

Jason K. Perry, jason@firstprinciples.com, Gilead Sciences, 333 Lakeside Dr, Foster City, CA 94404, Jamil Tahir-Kheli, Materials and Process Simulation Center (MSC) (139-74), California Institute of Technology, Pasadena, CA 91125, and William A. Goddard III, wag@wag.caltech.edu, Materials and Process Simulation Center, California Insitute of Technology, California Insitute of Technology, 139-74, Pasadena, CA 91125.
We have performed hybrid density functional (Becke-3-Lee-Yang-Parr) calculations on a number of doped and undoped cuprate superconductors. In contrast to the band structures derived from non-hybrid local density approximation methods, doping is clearly seen to affect out of plane orbitals rather than in plane orbitals. Specifically, doped holes appear in the z2/apical Opz orbitals of La2-xSrxCuO4 and in the chain orbitals of YBa2Cu3O7-y. Furthermore, small changes in the crystal geometry can greatly affect the band structure. In particular, movement of the apical O in La2-xSrxCuO4 influences whether the doped hole is localized on a single center or delocalized over multiple centers. Similar perturbations in the formally undoped YBa2Cu3O7 spell the difference between localized and delocalized chain orbitals. This work provides an ab initio foundation for the recent theory of high temperature superconductivity proposed by Tahir-Kheli and Goddard.
 

Bold Predictions in Theoretical Chemistry: A Poster Session in Honor of One of the Boldest, Bill Goddard, on the Occasion of his 70th Birthday
7:30 PM-9:30 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Computers in Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007