Why quantum dot simulation domain must contain multi-million atoms?

By Muhammad Usman

Purdue University

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The InGaAs quantum dots obtained from the self-assembly growth process are heavily strained. The long-range strain and piezoelectric fields significantly modifies the electronic structure of the quantum dots. This imposes a critical constraint on the minimum size of the simulation domain to study the electronic and optical spectra of these nano-structures. The aim of this presentation is to carry out a very simple numerical experiment by performing systematic simulations of an experimentally grown and measured InAs quantum dot system and determine the minimum size of the simulation domain required to reproduce the experimental evidence. Our simulations demonstrate that the minimum size of the simulation domain must contain ~8 million atoms. Our results will serve as a useful guide for the computational physicists working on the modeling and simulations of the quantum dot devices.


Dr. Muhammad Usman was graduated from Electrical & Computer Engineering Department, Purdue University in August 2010. He is currently working as a researcher at Tyndall National Institute. His area of research is theory, modeling, simulation, and computation of the III-V semiconductor materials, their alloys, hetero-structures, and optoelectronic devices. He is closely affiliated with NCN and nanoHub.org. He is a junior member of IEEE, American Physical Society (APS), and Material Research Society (MRS). Further information about Dr. Usman's work can be found at his web page: http://web.ics.purdue.edu/~usman


The use of the computational resources from nanohub.org and RCAC Purdue University is acknowledged.

This work was presented as a part of my PhD thesis at Purdue University.


1. M. Usman et al., J. of Applied Physics 109, 104510, 2011;

2. M. Usman et al., Physical Review B 84, 115321, 2011;

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Researchers should cite this work as follows:

  • Muhammad Usman (2013), "Why quantum dot simulation domain must contain multi-million atoms? ," https://nanohub.org/resources/16192.

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