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TE/TM polarisation response of InAs/GaAs quantum dot bilayers
22 Oct 2015 | | Contributor(s):: Muhammad Usman
Quantum dot bilayers are strong candidates for the design of telecom devices working at 1300 nm wavelength range. Here we analyse - both experimentally and theoretically - their optical and polarisation properties.
Exploring New Channel Materials for Nanoscale CMOS
28 Jun 2013 | | Contributor(s):: Anisur Rahman
The improved transport properties of new channel materials, such as Ge and III-V semiconductors, along with new device designs, such as dual gate, tri gate or FinFETs, are expected to enhance the performance of nanoscale CMOS devices. Novel process techniques, such as ALD, high-# dielectrics,...
Why quantum dot simulation domain must contain multi-million atoms?
11 Jan 2013 | | Contributor(s):: Muhammad Usman
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...
Polarization Response of Multi-layer InAs Quantum Dot Stacks
25 Oct 2011 | | Contributor(s):: Muhammad Usman
Recent experimental measurements, without any theoretical guidance, showed that isotropic polarization response can be achieved by increasing the number of QD layers in a QD stack. In this work, we analyse the polarization response of multi-layer quantum dot stacks containing up to nine quantum...
Quantitative Modeling and Simulation of Quantum Dots
18 Apr 2011 | | Contributor(s):: Muhammad Usman
Quantum dots grown by self-assembly process are typically constructed by 50,000 to 5,000,000 structural atoms which confine a small, countable number of extra electrons or holes in a space that is comparable in size to the electron wavelength. Under such conditions quantum dots can be...
Quantum Dot Wave Function (Quantum Dot Lab)
02 Feb 2011 | | Contributor(s):: Gerhard Klimeck, David S. Ebert, Wei Qiao
Electron density of an artificial atom. The animation sequence shows various electronic states in an Indium Arsenide (InAs)/Gallium Arsenide (GaAs) self-assembled quantum dot.
Self-Assembled Quantum Dot Structure (pyramid)
02 Feb 2011 | | Contributor(s):: Gerhard Klimeck, Insoo Woo, Muhammad Usman, David S. Ebert
Pyramidal InAs Quantum dot. The quantum dot is 27 atomic monolayers wide at the base and 15 atomic monolayers tall.
Quantum Dot Wave Function (still image)
31 Jan 2011 | | Contributor(s):: Gerhard Klimeck, David S. Ebert, Wei Qiao
Electron density of an artificial atom. The image shown displays the excited electron state in an Indium Arsenide (InAs) / Gallium Arsenide (GaAs) self-assembled quantum dot.
Self-Assembled Quantum Dot Wave Structure
31 Jan 2011 | | Contributor(s):: Gerhard Klimeck, Insoo Woo, Muhammad Usman, David S. Ebert
A 20nm wide and 5nm high dome shaped InAs quantum dot grown on GaAs and embedded in InAlAs is visualized.
InAs: Evolution of iso-energy surfaces for heavy, light, and split-off holes due to uniaxial strain.
25 May 2010 | | Contributor(s):: Abhijeet Paul, Denis Areshkin, Gerhard Klimeck
Movie was generated using Band Structure Lab tool at nanoHUB and allows to scan over four parameters:Hole energy measured from the top of the corresponding band (i.e. the origin of energy scales for LH and SOH is different)Strain direction: , , Carrier type: LH, HH, SOHStrain...
Electronic band structure
12 Apr 2010 | | Contributor(s):: Saumitra Raj Mehrotra, Gerhard Klimeck
In solid-state physics, the electronic band structure (or simply band structure) of a solid describes ranges of energy in which an electron is "forbidden" or "allowed". The band structure is also often called the dispersion or the E(k) relationship. It is a mathematical relationship between the...
Comparison of PCPBT Lab and Periodic Potential Lab
10 Aug 2009 | | Contributor(s):: Abhijeet Paul, Samarth Agarwal, Gerhard Klimeck, Junzhe Geng
This small presentation provides information about the comparison performed for quantum wells made of GaAs and InAs in two different tools. This has been done to benchmark the results from completely two different sets of tools and validate the obtained results. In this presentation we provide...