California New Age Physics: Sunshine, Crystals, and Quantum Geometry of Bands

Datum

12.09.2018

Zeit

14:00 - 16:00

Sprecher

Prof. Joseph W. Orenstein

Zugehörigkeit

UC Berkeley and Materials Research Division

Sprache

en

Hauptthema

Materialien

Andere Themen

Chemie, Physik, Materialien

Host

Prof. Dr. A. P. Mackenzie

Beschreibung

Nonlinear optical properties of materials are important as tools in basic research and optical technology. Recently there has been a tremendous upsurge of interest in optical nonlinear effects, especially in crystals with curved bandstructure geometry. Such materials are candidates for applications based on the conversion of light to dc current. In this talk I describe our discovery that a family of Weyl semimetals has by far the largest second-order susceptibility of any previously known crystal. In puzzling over this result, we uncovered a surprising theorem relating the strength of optical nonlinearity to a gauge invariant property of the bandstructure that unites nonlinear optics with the celebrated “modern theory of polarization.” This gauge invariant provides a new strategy for algorithmic computational searches for nonlinear materials with optimal response functions.

Links

• MPI CPfS

Letztmalig verändert: 13.09.2018, 02:06:09