Ab-initio Calculation of Nonlinear Optical Susceptibilities in Germanium Quantum Dots
Paper in proceeding, 2019

Using Time Independent Density Functional Theory (TIDFT) implemented in SIESTA (R) we calculated the 2nd order and 3rd order nonlinear optical susceptibilities of small Germanium Quantum Dots (GeQD). We observe that the symmetry breaking due to surface termination enhances chi((2)) up to 299.1 pm/V which promises a strong Second Harmonic Generation (SHG) in GeQDs. Diagonal components for chi((2)) tensor are 52.5, 11.2, 299.1 pm/V, for xxx, yyy and zzz, respectively. The 3rd order susceptibility, chi((3)), is within the range of (0.2-0.4) x 10(-18) m(2)/V-2 which is close to the reported experimental values of bulk Germanium. This study suggests possibilities of enhancing SHG in GeQDs through symmetry breaking via strain and surface termination/reconstruction as well as suitability of this fast and less-computationally intensive Density Functional Theory (DFT)-based method in predicting nonlinear optical susceptibilities of nano structures.

Quantum Dots

SIESTA (R)

nonlinear optics

DFT

Germanium

second order susceptibility

Author

Shadli Islam

Texas A&M University

Harsh Shah

Texas A&M University

Daryoush Shiri

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Reza Nekovei

Texas A&M University

Amit Verma

Texas A&M University

2018 IEEE 13TH NANOTECHNOLOGY MATERIALS AND DEVICES CONFERENCE (NMDC)

2378-377X (ISSN)

113-116
9781538610169 (ISBN)

Subject Categories

Other Physics Topics

Theoretical Chemistry

Condensed Matter Physics

DOI

10.1109/NMDC.2018.8605886

More information

Latest update

10/6/2023