1,721,075 research outputs found
Theory of Electron Transport in Semiconductors: A Pathway from Elementary Physics to Nonequilibrium Green Functions
No full textThis book describes in details the theory of the electron transport in the materials and structures at the basis of modern micro- and nano-electronics. It leads and accompanies the reader, through a step-by-step derivation of all calculations, from the basic laws of classical and quantum physics up to the most modern theoretical techniques, such as nonequilibrium Green functions, to study transport properties of both semiconductor materials and modern low-dimensional and mesoscopic structures
Analysis of quantum features in transport theory from a quantum monte carlo approach
No full textWE PRESENT A mONTE cARLO APPROACH TO THE SOLUTION OF THE Liouvlle equation for an ensemble of carriers in semiconductors
Wave-packet analysis of electron-phonon interaction in the Wigner formalism
No full textA theoretical Wigner-function approach to the study of quantum transport in open systems in presence of phonon scattering is presented. It is shown here that in order to solve the Wigner equation in its integral form the knowledge of the Wigner function at all points of the phase space at an initial time t0 can be substituted by the knowledge of the same function inside the region of interest at t0 and on its boundary at all times t′ less then the observation time t. The theory has been applied to calculate the current associated with electron quantum transport across given potential profiles and in presence of phonon scattering
The Wigner-function approach to non-equilibrium electron transport
No full textThe Wigner-function (WF) approach to quantum electron transport in semiconductors is reviewed in this paper. The main definitions and properties related to the WF are presented, with a discussion of the various forms of the dynamical equations that govern its evolution. Monte Carlo solutions of such equations are also discussed. Interactions of electrons with applied fields, potential profiles, and phonons are analysed in detail. Finally, several physical applications are presented. Each topic has been developed from basic principles for the benefit of interested readers who are not experts in the particular subjects discussed in this paper
Dinamica elettronica in sistemi mesoscopici
No full textNegli ultimi anni, la continua riduzione delle dimensioni dei dispositivi a semiconduttore ha reso chiaro quanto sia necessario un approccio quantistico al problema del trasporto di carica. Il metodo, basato sul formalismo della funzione di Wigner si e` mostrato particolarmente adatto a questo scopo, sia per l'analogia formale con la descrizione classica in termini di spazio delle fasi, sia per il naturale utilizzo delle condizioni al contorno. Tra i risultati principali fin' ora ottenuti si ha una possibile spiegazione della sorprendente attendibilita` dell'approccio semiclassico (equazione di Boltzmann) e l'influenza della distanza dei contatti sulla dinamica elettronica interna ad un sistema mesoscopico
Wigner Paths for Quantum Transport
No full textA Monte Carlo algorithm based on the concept of Wigner paths has been developed to study quantum transport in mesoscopic systems in strict analogy with the traditional Monte Carlo simulation used to solve the Boltzmann transport equation. Scatterings with both phonons and impurities can be accounted for. As regards a structure potential profile the effect of the corresponding classical force can be inserted in the dynamics of the free flight, while quantum effects due to rapid potential variations are included as a special scattering mechanism
Analysis of the stationary and transient autocorrelation function in semiconductors
No full textA theoretical analysis of velocity fluctuations in semiconductors is presented both in steady state and in transient regime conditions
Diagonal and off-diagonal contributions to autocorrelation of velocity fluctuations in semiconductors
No full textA theoretical analysis of velocity fluctuations in semiconductors is presented
30 years of HCIS
No full textOn the occasion of the 30th anniversary of the HCIS conference, we would like to provide a general, although necessarily not exhaustive, picture of how the conference has changed over the years and of how the natural evolution of research has influenced its various editions. By performing a statistical analysis of specific sets of data, we try to identify some characteristic trends that, we believe, can contribute to a better understanding of how our field of research has been developing in the last three decades. On request of the editor, we added the data relative to HCIS-13
Electron dynamics inside short-coherence systems
No full textWe present theoretical results on electron dynamics inside nanometric systems, where the coherence of the electron ensemble is maintained in a very short region. The contacts are supposed to spoil such a coherence, therefore the interference processes between the carrier wavefunction and the internal potential profile can be affected by the proximity of the contacts. The problem has been analysed by using the Wigner-function formalism. For very short devices, transport properties, such as tunnelling through potential barriers, are significantly influenced by the distance between the contacts
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