Ballistic and diffusive conductance
Density of states
Number of modes
Very different from what is taught in standard courses, “Fundamentals of Current Flow” provides a unified conceptual framework for ballistic and diffusive transport of both electrons and phonons- essential information for understanding nanoelectronic devices.
The traditional description of electronic motion through a solid is based on diffusive transport, which means that the electron takes a random walk from the source to the drain of a transistor, for example. However, modern nanoelectronic devices often have channel lengths comparable to a mean free path so that electrons travel ballistically, or “like a bullet.”
This course is part of a Purdue initiative that aims to complement the expertise that students develop with the breadth at the edges needed to work effectively in today’s multidisciplinary environment. These serious short courses require few prerequisites and provide a general framework that can be filled in with self-study when needed.
Students taking this course will be required to complete two (2) proctored exams using the edX online Proctortrack software.
Fundamentals of Current Flow is one course in a growing suite of unique, 1-credit-hour short courses being developed in an edX/Purdue University collaboration. Students may elect to pursue a verified certificate for this specific course alone or as one of the six courses needed for the edX/Purdue MicroMasters program in Nano-Science and Technology. For further information and other courses offered and planned, please see the Nano-Science and Technology page. Courses like this can also apply toward a Purdue University MSECE degree for students accepted into the full master’s program.
Week 1: The New Perspective
1.2 Two Key Concepts
1.3 Why Electrons Flow
1.4 Conductance Formula
1.5 Ballistic (B) Conductance
Week 2: The New Perspective (Continued)
1.6 Diffusive (D) Conductance
1.7 Connecting B to D
1.8 Angular Averaging
1.9 Drude Formula
1.10 Summing Up
Week 3: Energy Band Model
2.2. E(p) or E(k) Relation
2.3. Counting States
2.4. Density of States
2.5. Number of Modes
Week 4: Energy Band Model (Continued)
2.6. Electron Density (n)
2.7. Conductivity vs. n
2.8 - 2.10 Bonus Lectures; NOT covered on exams _
3.1 Introduction _
* 3.2 A New Boundary
3.3 Quasi-Germi Levels (QFL's)
Week 5: Energy Band Model (continued)
3.4 Current from QFL's
3.5 Landauer formulas
* 3.6 - 3.10 Bonus Lectures; NOT covered on exams
Epilog: Looking Forward-From Semiclassical to Quantum
Text: S. Datta, "Lessons from Nanoelectronics", Part A: Basic Concepts,
World Scientific, Second Edition 2017
The manuscript will be available for download on the course's website.
Undergraduate degree in engineering or the physical sciences, specifically differential equations, and linear algebra.