Excitons in Coupled Double Quantum Wells PDF Download

Author: Sang Yup Kim
Publisher:
ISBN:
Category :
Languages : en
Pages : 312

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Author: `tepán Uxa
Publisher: LAP Lambert Academic Publishing
ISBN: 9783846519325
Category :
Languages : en
Pages : 92

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Book Description
Advanced epitaxial techniques such as molecular beam epitaxy or metal-organic chemical vapour deposition have made it possible to grow interfaces between two semiconductors flat up to one atomic monolayer. The possibility of fabricating a heterostructure of strictly-defined parameters, a quasi-two-dimensional nature and sharp density of states, has stimulated both theoretical and experimental research and shortly found many applications including LEDs, lasers, high electron mobility transistors, IR photodetectors, etc. In this work a detailed study of optical properties of excitons in double quantum wells subject to magnetic and electric fields is presented. Starting from the well-known Luttinger formulae we developed an efficient way to solve the Schrodinger equation of a coulombically-bound pair electron-hole forming an exciton. The results are illustrated on relevant figures, giving an opportunity to better understand the effects of external fields on the studied system. The book should shed light on methods used for calculations of magnetooptical properties and may be useful to anyone who is interested in theoretical or experimental research on semiconductor quantum structures.

Author: Chih-Wei Eddy Lai
Publisher:
ISBN:
Category :
Languages : en
Pages : 362

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Author: Jason Leonard
Publisher: Springer
ISBN: 3319697331
Category : Technology & Engineering
Languages : en
Pages : 67

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Book Description
This thesis presents results crucial to the emerging field of indirect excitons. These specially designed quasiparticles give the unique opportunity to study fundamental properties of quantum degenerate Bose gases in semiconductors. Furthermore, indirect excitons allow for the creation of novel optoelectronic devices where excitons are used in place of electrons. Excitonic devices are explored for the development of advanced signal processing seamlessly coupled with optical communication. The thesis presents and describes the author's imaging experiments that led to the discovery of spin transport of excitons. The many firsts presented herein include the first studies of an excitonic conveyer, leading to the discovery of the dynamical localization-delocalization transition for excitons, and the first excitonic ramp and excitonic diode with no energy-dissipating voltage gradient.

Author: Andrea D'Andrea
Publisher: CRC Press
ISBN: 9780854984138
Category : Technology & Engineering
Languages : en
Pages : 380

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Book Description
Optics of Excitons in Confined Systems provides an overview of research in semiconductors that exhibit resonance enhanced optical nonlinearities in the frequency range close to the valence-conduction band gap. The book is divided into the following sections: quantum wells, wires, and dots; superlattices; nonlinear optical properties of confined systems; and effects of external fields on confined systems. Topics range from fundamental theory to more applied aspects of excitons in confined sytems.

Author: Jason Leonard
Publisher: Springer
ISBN: 9783319888347
Category : Technology & Engineering
Languages : en
Pages : 59

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Book Description
This thesis presents results crucial to the emerging field of indirect excitons. These specially designed quasiparticles give the unique opportunity to study fundamental properties of quantum degenerate Bose gases in semiconductors. Furthermore, indirect excitons allow for the creation of novel optoelectronic devices where excitons are used in place of electrons. Excitonic devices are explored for the development of advanced signal processing seamlessly coupled with optical communication. The thesis presents and describes the author's imaging experiments that led to the discovery of spin transport of excitons. The many firsts presented herein include the first studies of an excitonic conveyer, leading to the discovery of the dynamical localization-delocalization transition for excitons, and the first excitonic ramp and excitonic diode with no energy-dissipating voltage gradient.

Author: Yuliya Yevgenyevna Kuznetsova
Publisher:
ISBN: 9781321451900
Category :
Languages : en
Pages : 67

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Book Description
This dissertation explores studies of transport of indirect excitons (bosonic quasiparticles composed of bound pairs of an electron and a hole confined to spatially separated layers) in GaAs coupled quantum wells. The small mass and long lifetime of indirect excitons result in a relatively high quantum degeneracy temperature and efficient cooling, making indirect excitons a model system for studies of physics of cold bosons. In addition, indirect excitons are optically active, electronically controllable and have long enough lifetimes that their transport distances can be accommodated by lithography. These properties make indirect excitons a promising system for creating excitonic devices. The direction of the research presented in this dissertation is thus twofold: studying fundamental physics of excitons, including transport, thermalization, coherence, spin currents, and properties in high magnetic fields, and realization of optical excitonic devices, such as traps and transistors.

Author: Joe Wilkes
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This thesis comprises a theoretical study of the dynamics of indirect excitons in coupled quantum wells at low lattice temperatures. The results of numerical simulations of the exciton photoluminescence pattern are presented and compared to available experimental data. The in-plane transport of quantum well excitons created by laser excitation is modeled using a non-linear drift-diffusion equation. Combined with a model of exciton relaxation thermodynamics, a complete description of the evolution of the exciton density and temperature is built. The optical decay of indirect excitons is included in the modeling. This is used to make predictions of the spatial photoluminescence patterns which have been observed experimentally. The transport of dipole orientated excitons via externally applied electrostatic potentials is also studied. The drift-diffusion equation is adapted to include the inplane electric field. This is done for some specific forms of the potential landscapes such as a linear potential energy gradient and a propagating lattice. These correspond to some recent experiments for which results are available. The combined theoretical and experimental studies reveal a deeper insight into the transport properties of indirect excitons. Finally, the external ring structure in the indirect exciton emission pattern is studied. Its formation is modeled using a set of coupled transport equations for electrons, holes and indirect excitons. The Coulomb interactions between all three species are incorporated in the model. It is shown that these interactions lead to an instability in the external ring and are responsible for its fragmentation into a periodic array of islands which has been observed experimentally.

Author: Smadar Ben-Tabou de-Leon
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 244

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Author: P. K. Bhattacharya
Publisher: IET
ISBN: 9780852968819
Category : Electronic books
Languages : en
Pages : 238

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Book Description
A finely-structured, state-of-the-art review on controlled building of atomic-scale mutilayers, where nanometric structures based on III-V semiconductors have attracted particular attention.