Activities

Seminars
Seminar on Theoretical and Computational Physics:
 Title  A general numerical approach to high harmonic generation in semiconductors


Speaker  Dr. Huynh Thanh Duc


Affiliation  Institute of Applied Mechanics and Informatics, HCM city


Date  Friday, 17062022


Time  10:00 AM


Location  Room 62, 6th floor, 2H building, 18 Hoang Quoc Viet, Cau Giay, Ha Noi


Abstract  It is well known that numerical diagonalization procedures using in the electronic band structure calculation result typically in an arbitrary phase factor of nondegenerate states and mix degenerate states in an arbitrary way for each value of the crystal momentum k. These ambiguities are problematic if one studies semiconductor optics in length gauge (E.r) since the matrix elements of the position operator involve a derivative of the wave functions with respect to k. This problem has been solved by implementing a proper gauge transformation. The length gauge turns out to be advantageous since it converges for a smaller number of bands than the velocity gauge and, in addition, enables a unique distinction between inter and intraband contributions. Our calculated results for highharmonic generation from GaAs are in good agreement with recent experimental data. Besides odd harmonics polarized parallel to the incident field our approach also describes even harmonics polarized perpendicular to the field which originate from the Berry curvature.
Google meet: meet.google.com/dgwepwatsi


Host person  Trần Minh Tiến


