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Unformatted text preview: Fall 2010 ECE 453 Lecture Notes #5 For Purdue ECE 453 students ONLY NOT FOR CIRCULATION ECE 453 Lecture Notes#5 Excerpted from (LNE) Lessons from nanoelectronics: A new perspective on transport 1. The bottomup approach 4 Introductory concepts 2. Why electrons flow 6 3. The elastic resistor 10 4. The new Ohm's law 14 Notes #1 5. Where is the resistance? 19 ***************************************************************** 6. Transverse modes 27 7. Drude formula 33 8. Kubo formula 38 Notes # 2 9. How realistic is an elastic resistor? 41 ***************************************************************** Semiclassical and quantum transport 10. Beyond low bias: The nanotransistor 44 Notes#3 11. Semiclassical Transport and the Scf method 50 ***************************************************************** 12. Resistance and uncertainty 56 13. Quantum Transport: Schrodinger to NEGF 63 Notes#4 14. Resonant tunneling and Anderson localization 68 ***************************************************************** 15. Coulomb blockade and Mott transition 72 16. Hall effect / QHE 78 Beyond voltages and currents 17. Thermoelectricity 83 Notes#5 18. Heat flow 88 ***************************************************************** 19. Spin flow 92 20. Spin transistor xx 21. Electronic Maxwell's demon xx 22. Physics in a grain of sand xx Supriyo Datta, [email protected] Purdue University World Scientific (2011), to be published Lessons from nanoelectronics: Copyright S. Datta [email protected] All Rights Reserved 72 15. Coulomb blockade and Mott transition Electronelectron interactions represent the single biggest problem in understanding the the properties of condensed matter in general. It is indeed fortunate that the picture of quasiindependent electrons moving in a selfconsistent potential U due to the other electrons works so well. But it is also true that some of the most intriguing properties arise from a failure of this simple picture. The basic issue in the present context can be understood by considering what the density of states D(E) represents. This concept is central to our discussion of conductance, which is given by G = q 2 D /2 t (same as Eq.(3.3)) Conduction involves an electron entering at the source and getting removed from the drain, but the process could as well be reversed. An electron could first be removed from the drain and then inserted from the source. The point is that the potential an electron feels is a little different for these processes. If there are N electrons ordinarily residing in the channel, then an electron coming in feels a potential due to all N of them U N. But if one electron has already left the channel then the incoming electron sees a potential due to one less electron, U (N1)....
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 Spring '10
 SupriyoDatta
 Electron, Thermoelectric effect, Copyright S. Datta, Supriyo Datta

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