###EE 724 – NANOELECTRONICS

**Academic Semester / Year: **

Spring 2017

**Professor who took the course**
Bhaskaran Muralidharan

**Motivation :**

As the name suggests the course focuses on analysis of devices in the nanoscale regime. These devices due to its very small dimensions cannot be analysed using classical physical equations like the diffusion equation used for analysing PN junction and MOSFETs. Therefore quantum mechanics and statistical mechanics becomes essential to analyse such devices. This course delineates us with the electron transport and the physics accompanied with it in modern day devices. It starts from the understanding of transport of one electron and later builds upon the concepts to define transport of large number of electrons in the diffusive regime. Recent devices like spin valves and spin transistors are also discussed using the concepts taught in class.

**Course Content **

**Part I – Semiclassical Transport**

1) Ballistic transport basics, elastic resistor model.

2) Bottom up view point, Landuer approach, connection with diffusive transport

3) Nano transistor, Drift-Diffusion

**Part II – Quantum Transport**

1) Schrodinger equation, Hamiltonian, density of states

2) Concept of bandstructure, graphene, nanotubes.

3) Non-equilibrium transport: NEGF Formalism and applications

**Part III – Spin Transport, Spintronics**

1) Concept of spinors and vectors

2) Magnetoresistance phenomenon, modelling spin valves

3) Spin Transfer Torque

**Part IV – Energy Transport**

1) Basic of thermoelectrics

2) Entropy and heat currents, connection with second law.

**Pre-requisite**

This course has no hard prerequisites but a basic understanding of Quantum Mechanics will greatly facilitate in understanding the concepts taught in the lectures. Simulations were needed to be performed in assignments so basic coding skills were assumed, especially in Python or MATLAB.
**Feedback on lectures:**

All the lectures were taught on the board so it is a must for a student to attend all lectures to have a good grasp of the concepts. After every part was finished the professor used to analyse a modern device using the concepts taught in that part. A good time was spent on the discussion of the first part and the second part. Only the basics of NEGF were taught as they are covered in detail in another course taken by the same professor. The last part felt a little rushed due to the lack of time. The pace of the lectures were moderate but missing a class after the midsems could pose a problem in understanding future concepts. The lectures were heavily derived from two books which are mentioned below.

**Evaluation:**

1) Quizzes – 20%

2) Assignment – 5%

3) Mid semester Examination – 25%

4) End Semester Examination – 50%

**Feedback on Exams and Assignments:**
There was only one assignment given which could be easily solved using the concepts taught in class. It was mostly based on simulation of devices so coding was necessary. The quizzes were moderately easy and mostly tested on theoretical concepts rather than numerical problems. The mid semester and end semester exams were lengthy but the question pattern were similar to the quizzes. One or two questions included introducing a new device which needed to be analysed. Overall the exams were moderate and needed constant working to finish the paper within the time limit.
**Difficulty level:**
The exams are based more on theoretical concepts rather than solving numerical problems, so a regular input in this course is required in order to grasp the concept and perform well. Overall the difficulty level of this course is moderate but it would be easy if a student has a good background in quantum mechanics.**Miscellaneous :**

**Attendance:**
A minimum attendance is required for the lectures. An attendance sheet was regularly passed in the class.

**Text Books:**
1) Lessons from Nanoelectronics: A New Perspective in Transport by Supriyo Dutta

2) Quantum Transport: Atom to Transistor by Supriyo Dutta

The above two books are the bibles for the course as the lectures are heavily derived from them.
**Reviewed By:** Pratik Brahma (pratikbrahma96@gmail.com)