93393 - ELECTRONIC FRONTIERS M

Conoscenze e abilità da conseguire

The course will address challenges in emerging technologies and architectures for intelligent systems, big data and internet of things, possibly changing year to year.

Contenuti

Electronic devices have reached dimensions of the order a few tens of nanometers which are comparable to the thermal wavelength of current carrying electrons. While in the past, working with devices of sized of the order a micrometers, simplified physical models could satisfactorily predict the electrical properties and characteristics of the devices themselves, a more accurate physical description of the electronic excitation spectrum (the ‘band structure’), of the collision processes affecting the motion of charge carriers, and of the transport itself is now required, as dealing with each family of devices (such as post-Si CMOS, transistors based on III-V compound semiconductors, carbon based devices, etc.) requires physically-based analysis.

This course deals with the three major issues mentioned above introducing the concepts necessary to investigate: 1. The electronic structure of small semiconductor structures starting from basic condensed-matter theory. 2. The nature of ‘elementary excitations’ (such as phonons, plasmons, interface and surface excitations, etc.) in terms of the many-body, second quantization language, 3. The interaction of electrons with these excitations, as well as photons, and, 4. The equations which govern electronic transport at the nanometer scale.

The material will be treated at a theoretical level requiring basic knowledge of classical and quantum mechanics and electromagnetism, but elements of solid-state physics and statistical mechanics will be discussed in class. Numerical issues will be discussed in dealing with the specific examples of the band structure of bulk semiconductors and nanometer-size structures (thin films, nanowires, graphene and C nanotubes. The subject of ‘second quantization’ (the equivalent of ‘quantum field theory’ in a condensed matter context) will be introduced within the specific examples of the Schrödinger field, of phonons, plasmons, and also of the electromagnetic field. Interactions between electrons and these excitations will be treated using first-order perturbation theory. Finally, the concept of the density matrix will be introduced to approach the problem of electronic transport starting from a quantum (Liouville-van Neumann) viewpoint to reaching the semiclassical picture of the Boltzmann equation.

Outline:

1. Crystals and elements of crystal structure
2. Energy bands in semiconductors. Use of the empirical pseudopotential method applied to nanometer-scale structures (thin films, graphene, nanowires, carbon nanotubes)
3. Single electron dynamics, energy levels, quantum confinement
4. Review of the Statistical Mechanics of electrons and holes
5. Lagrangian and Hamiltonian theory, canonical quantization, second quantization
6. Elementary excitations in solids, phonons, plasmons
7. Dielectric response (also in reduced dimensionality systems)
8. Scattering theory: Generalities, impurity scattering, electron-phonon scattering
9. Radiative processes
10. Semiclassical Theory of Charge Transport in Solids: From the Density Matrix to the Boltzmann transport equation

Testi/Bibliografia

• The course will be based on Lecture Notes that will be made available. They are based on the textbook: Massimo V. Fischetti and William G. Vandenberghe, Advanced Physics of Semiconductors. Electronic Properties and Transport", Series of `Graduate Texts in Physics' (Springer, New York, 2016).
  
• An excellent reference for the course is: Brian K. Ridley, "Quantum Processes in Semiconductors" (Clarendon Press- Oxford University Press, New York, 1999).
• Chapter 3 below: For the single-particle dynamics: C. Kittel, “Introduction to Solid State Physics”, (John Wiley and Sons, New York, 1971).
• Chapter 5: For the Lagrange and Hamilton formulation of classical mechanics H. Goldstein, “Classical Mechanics”, (Addison-Wesley, Reading, Massachusetts, 1980). For a more complete presentations (perhaps too complete) of second quantization: A. L. Fetter and J. D. Walecka, “Quantum Theory of Many Particle Systems” (McGraw Hill, New York, 1971).
• Chapter 4, 8 and 10: K. Hess, “Advanced Theory of Semiconductor Devices”, (Prentice Hall, Englewood Cliffs, New Jersey 1988).

Metodi didattici

Lectures will be given remotely via MS Teams using PowerPoint slides. The lectures will also be recorded.

Modalità di verifica e valutazione dell'apprendimento

In addition to the final exam, that will be the main assessment method, homework assignments will be given on a (roughly) biweekly basis. They will be not be used to determine the final grade, but they will be useful to help the students assess their understanding of the material.

Strumenti a supporto della didattica

As stated above regarding "teaching methods", lectures will be given remotely via MS Teams using PowerPoint slides. The lectures will also be recorded and the PowerPoint slides and Lecture Notes will be made available.

Additionally, clarifications, discussions, or any other help can be requested via email and "office hours" can be held via MS Teams upon request.

Orario di ricevimento

Consulta il sito web di Massimo Fischetti