[Audio] Nanoelectronics and the Meaning of Resistance
https://nanohub.org/resources/5279
Mon, 27 Jun 2016 01:10:51 +0000HUBzero - The open source platform for scientific and educational collaborationThe purpose of this series of lectures is to introduce the "bottom-up" approach to nanoelectronics using concrete examples. No prior knowledge of quantum mechanics or statistical mechanics is assumed; however, familiarity with matrix algebra will be helpful for some topics.
Day 1: What and where is the resistance?
Day 2: Quantum transport
Day 3: Spins and magnets
Day 4: Maxwell’s demon
Day 5: Correlations and entanglement
Romanian translation of this page.nanoHUB.orgsupport@nanohub.orgnobottom up approach, datta, Maxwell\'s Demon, nanoelectronics, NEGF, quantum transport, short course, transport/quantumSupriyo Dattaen-gbCopyright 2016 nanoHUB.orgResourcesLecture 1A: What and where is the resistance?
https://nanohub.org/resources/5211
Figure 1Objective: To introduce a simple quantitative model that highlights the essential parameters that determine electrical conduction: the density of states in the channel, D and the rates at which electrons hop in and out of the two contacts, labeled source and drain. This model is used to explain diverse phenomena such as (1) why a small conductor has a maximum conductance that it cannot exceed even with the best of contacts, (2) how this conductance quantum evolves into Ohm’s law for large conductors, (3) how even a hydrogen atom can exhibit thermoelectric effects, (4) how even symmetric devices can be rectifying due to asymmetric electrostatics, and (5) how the “voltage” varies spatially inside a nanoscale device.This lecture is part 1 of 2.https://nanohub.org/site/resources/2008/08/05258/2008.07.14-l1a-datta.mp3Figure 1Objective: To introduce a simple quantitative model that highlights the essential parameters that determine electrical conduction: the density of states in the channel, D and the rates at which electrons hop in and out of the two contacts, labeled source and drain. This model is used to explain diverse phenomena such as (1) why a small conductor has a maximum conductance that it cannot exceed even with the best of contacts, (2) how this conductance quantum evolves into Ohm’s law for large conductors, (3) how even a hydrogen atom can exhibit thermoelectric effects, (4) how even symmetric devices can be rectifying due to asymmetric electrostatics, and (5) how the “voltage” varies spatially inside a nanoscale device.This lecture is part 1 of 2.nocourse lecture, density of states, dev/funded by NCN@Purdue, DOS, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, nanotransistors, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:29 +0000https://nanohub.org/site/resources/2008/08/05258/2008.07.14-l1a-datta.mp3Lecture 3A: Spin Transport
https://nanohub.org/resources/5269
Figure 3Objective: To extend the model from Lectures 1 and 2 to include electron spin. Every electron is an elementary “magnet” with two states having opposite magnetic moments. Usually this has no major effect on device operation except to increase the conductance by a factor of two.But it is now possible to inject, detect and manipulate spins in a controlled way and even use them to manipulate nanometer-sized magnets. The extended model will be used to describe such phenomena including spin-Hall effect, tunneling magnetoresistance (TMR) and spin-torque devices.This lecture is part 1 of 2.https://nanohub.org/site/resources/2008/08/05287/2008.07.16-l3a-datta.mp3Figure 3Objective: To extend the model from Lectures 1 and 2 to include electron spin. Every electron is an elementary “magnet” with two states having opposite magnetic moments. Usually this has no major effect on device operation except to increase the conductance by a factor of two.But it is now possible to inject, detect and manipulate spins in a controlled way and even use them to manipulate nanometer-sized magnets. The extended model will be used to describe such phenomena including spin-Hall effect, tunneling magnetoresistance (TMR) and spin-torque devices.This lecture is part 1 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, Hall effect, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, spintronics, transport/quantum, tunnelingSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05287/2008.07.16-l3a-datta.mp3Lecture 5A: Correlations and Entanglement
https://nanohub.org/resources/5273
Objective: To relate the one-electron picture used throughout these lectures to the more general but less tractable many-particle picture that underlies it. We introduce this new viewpoint using the example of Coulomb blockaded electronic devices that are difficult to model within the picture developed so far, but can be understood fairly simply in terms of a many-electron picture. This picture is then used to introduce the concept of entangled states possible approaches to extending the NEGF-Landauer framework from Lectures 1 through 4 to model correlations and entanglements. The overall message is that while there has been enormous progress in our understanding in the last twenty years and the resulting NEGF-Landauer approach provides a powerful framework for a wide variety of problems. But the approach has its limitations and there are important conceptual issues that have to be resolved to take transport theory to its next level.This lecture is in video format only. This is part 1 of 2.https://nanohub.org/site/resources/2008/08/05301/2008.07.18-l5a-datta.mp3Objective: To relate the one-electron picture used throughout these lectures to the more general but less tractable many-particle picture that underlies it. We introduce this new viewpoint using the example of Coulomb blockaded electronic devices that are difficult to model within the picture developed so far, but can be understood fairly simply in terms of a many-electron picture. This picture is then used to introduce the concept of entangled states possible approaches to extending the NEGF-Landauer framework from Lectures 1 through 4 to model correlations and entanglements. The overall message is that while there has been enormous progress in our understanding in the last twenty years and the resulting NEGF-Landauer approach provides a powerful framework for a wide variety of problems. But the approach has its limitations and there are important conceptual issues that have to be resolved to take transport theory to its next level.This lecture is in video format only. This is part 1 of 2.noCoulomb blockade, course lecture, dev/funded by NCN@Purdue, entanglement, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05301/2008.07.18-l5a-datta.mp3Lecture 2A: Quantum Transport
https://nanohub.org/resources/5263
Figure 2Objective: To extend the simple model from Lectures 1 into the full-fledged Non-equilibrium Green’s Function (NEGF) – Landauer model by introducing a spatial grid of N points and turning numbers like into (NxN) matrices like , with incoherent scattering introduced through . This model will be used to provide a quantitative description of key experiments such as the conductance of point contacts and the quantum Hall effect and also to introduce key concepts like transverse modes, spectral functions and density matrices.This lecture is part 1 of 2.https://nanohub.org/site/resources/2008/08/05267/2008.07.15-l2a-datta.mp3Figure 2Objective: To extend the simple model from Lectures 1 into the full-fledged Non-equilibrium Green’s Function (NEGF) – Landauer model by introducing a spatial grid of N points and turning numbers like into (NxN) matrices like , with incoherent scattering introduced through . This model will be used to provide a quantitative description of key experiments such as the conductance of point contacts and the quantum Hall effect and also to introduce key concepts like transverse modes, spectral functions and density matrices.This lecture is part 1 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05267/2008.07.15-l2a-datta.mp3Spins and Magnets (Whiteboard lecture), Part 1
https://nanohub.org/resources/6041
Whiteboard version of approximately the same material covered in Lectures 3A/3B.https://nanohub.org/site/resources/2008/12/06062/2009.01.06-datta-part1.mp3Whiteboard version of approximately the same material covered in Lectures 3A/3B.nofrom Purdue, hosted/taped by NCN@Purdue, Magnetic, nanoelectronics, quantum transport, spintronics, transport/quantum, tutorialSupriyo DattaSupriyo DattaOnline PresentationsTue, 06 Jan 2009 17:11:34 +0000https://nanohub.org/site/resources/2008/12/06062/2009.01.06-datta-part1.mp3Lecture 1B: What and where is the resistance?
https://nanohub.org/resources/5248
Figure 1Objective: To introduce a simple quantitative model that highlights the essential parameters that determine electrical conduction: the density of states in the channel, D and the rates at which electrons hop in and out of the two contacts, labeled source and drain. This model is used to explain diverse phenomena such as (1) why a small conductor has a maximum conductance that it cannot exceed even with the best of contacts, (2) how this conductance quantum evolves into Ohm’s law for large conductors, (3) how even a hydrogen atom can exhibit thermoelectric effects, (4) how even symmetric devices can be rectifying due to asymmetric electrostatics, and (5) how the “voltage” varies spatially inside a nanoscale device.This lecture is part 2 of 2.https://nanohub.org/site/resources/2008/08/05262/2008.07.14-l1b-datta.mp3Figure 1Objective: To introduce a simple quantitative model that highlights the essential parameters that determine electrical conduction: the density of states in the channel, D and the rates at which electrons hop in and out of the two contacts, labeled source and drain. This model is used to explain diverse phenomena such as (1) why a small conductor has a maximum conductance that it cannot exceed even with the best of contacts, (2) how this conductance quantum evolves into Ohm’s law for large conductors, (3) how even a hydrogen atom can exhibit thermoelectric effects, (4) how even symmetric devices can be rectifying due to asymmetric electrostatics, and (5) how the “voltage” varies spatially inside a nanoscale device.This lecture is part 2 of 2.nocourse lecture, density of states, dev/funded by NCN@Purdue, DOS, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, nanotransistors, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05262/2008.07.14-l1b-datta.mp3Lecture 3B: Spin Transport
https://nanohub.org/resources/5270
Figure 3Objective: To extend the model from Lectures 1 and 2 to include electron spin. Every electron is an elementary “magnet” with two states having opposite magnetic moments. Usually this has no major effect on device operation except to increase the conductance by a factor of two.But it is now possible to inject, detect and manipulate spins in a controlled way and even use them to manipulate nanometer-sized magnets. The extended model will be used to describe such phenomena including spin-Hall effect, tunneling magnetoresistance (TMR) and spin-torque devices.This lecture is part 2 of 2.https://nanohub.org/site/resources/2008/08/05291/2008.07.16-l3b-datta.mp3Figure 3Objective: To extend the model from Lectures 1 and 2 to include electron spin. Every electron is an elementary “magnet” with two states having opposite magnetic moments. Usually this has no major effect on device operation except to increase the conductance by a factor of two.But it is now possible to inject, detect and manipulate spins in a controlled way and even use them to manipulate nanometer-sized magnets. The extended model will be used to describe such phenomena including spin-Hall effect, tunneling magnetoresistance (TMR) and spin-torque devices.This lecture is part 2 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, Hall effect, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, spintronics, transport/quantum, tunnelingSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05291/2008.07.16-l3b-datta.mp3Lecture 5B: Correlations and Entanglement
https://nanohub.org/resources/5274
Objective: To relate the one-electron picture used throughout these lectures to the more general but less tractable many-particle picture that underlies it. We introduce this new viewpoint using the example of Coulomb blockaded electronic devices that are difficult to model within the picture developed so far, but can be understood fairly simply in terms of a many-electron picture. This picture is then used to introduce the concept of entangled states possible approaches to extending the NEGF-Landauer framework from Lectures 1 through 4 to model correlations and entanglements. The overall message is that while there has been enormous progress in our understanding in the last twenty years and the resulting NEGF-Landauer approach provides a powerful framework for a wide variety of problems. But the approach has its limitations and there are important conceptual issues that have to be resolved to take transport theory to its next level.This lecture is in video format only. This is part 2 of 2.https://nanohub.org/site/resources/2008/08/05304/2008.07.18-l5b-datta.mp3Objective: To relate the one-electron picture used throughout these lectures to the more general but less tractable many-particle picture that underlies it. We introduce this new viewpoint using the example of Coulomb blockaded electronic devices that are difficult to model within the picture developed so far, but can be understood fairly simply in terms of a many-electron picture. This picture is then used to introduce the concept of entangled states possible approaches to extending the NEGF-Landauer framework from Lectures 1 through 4 to model correlations and entanglements. The overall message is that while there has been enormous progress in our understanding in the last twenty years and the resulting NEGF-Landauer approach provides a powerful framework for a wide variety of problems. But the approach has its limitations and there are important conceptual issues that have to be resolved to take transport theory to its next level.This lecture is in video format only. This is part 2 of 2.noCoulomb blockade, course lecture, dev/funded by NCN@Purdue, entanglement, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05304/2008.07.18-l5b-datta.mp3Spins and Magnets (Whiteboard lecture), Part 2
https://nanohub.org/resources/6063
Whiteboard version of approximately the same material covered in Lectures 3A/3B.https://nanohub.org/site/resources/2008/12/06065/2009.01.06-datta-part2.mp3Whiteboard version of approximately the same material covered in Lectures 3A/3B.nofrom Purdue, hosted/taped by NCN@Purdue, iTunes U, Magnetic, nanoelectronics, quantum transport, spintronics, transport/quantum, tutorialSupriyo DattaSupriyo DattaOnline PresentationsTue, 06 Jan 2009 17:11:34 +0000https://nanohub.org/site/resources/2008/12/06065/2009.01.06-datta-part2.mp3Lecture 2B: Quantum Transport
https://nanohub.org/resources/5268
Figure 2Objective: To extend the simple model from Lectures 1 into the full-fledged Non-equilibrium Green’s Function (NEGF) – Landauer model by introducing a spatial grid of N points and turning numbers like into (NxN) matrices like , with incoherent scattering introduced through . This model will be used to provide a quantitative description of key experiments such as the conductance of point contacts and the quantum Hall effect and also to introduce key concepts like transverse modes, spectral functions and density matrices.This lecture is part 2 of 2.https://nanohub.org/site/resources/2008/08/05283/2008.07.15-l2b-datta.mp3Figure 2Objective: To extend the simple model from Lectures 1 into the full-fledged Non-equilibrium Green’s Function (NEGF) – Landauer model by introducing a spatial grid of N points and turning numbers like into (NxN) matrices like , with incoherent scattering introduced through . This model will be used to provide a quantitative description of key experiments such as the conductance of point contacts and the quantum Hall effect and also to introduce key concepts like transverse modes, spectral functions and density matrices.This lecture is part 2 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, hosted/taped by NCN@Purdue, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05283/2008.07.15-l2b-datta.mp3Lecture 4A: Energy Exchange and Maxwell\'s Demon
https://nanohub.org/resources/5271
Figure 4Objective: To incorporate distributed energy exchange processes into the previous models from lectures 1 through 3 which are based on a "Landauer-like picture" where the Joule heating associated with current flow occurs entirely in the two contacts.Although there is experimental evidence that this idealization is not too far from the truth in many nanodevices of today, dissipation generally occurs throughout the channel. Moreover there is great interest in energy conversion devices that convert heat into electricity or use electrical energy to pump heat. Our purpose here is (1) to describe the basic principles that must be obeyed by any model for energy conversion processes in order to comply with the laws of thermodynamics and (2) to convey the insights that nanodevices provide into the subtle issues of irreversibility that Boltzmann struggled with over a century ago when he constructed the first transport theory.This lecture is part 1 of 2.https://nanohub.org/site/resources/2008/08/05295/2008.07.17-l4a-datta.mp3Figure 4Objective: To incorporate distributed energy exchange processes into the previous models from lectures 1 through 3 which are based on a "Landauer-like picture" where the Joule heating associated with current flow occurs entirely in the two contacts.Although there is experimental evidence that this idealization is not too far from the truth in many nanodevices of today, dissipation generally occurs throughout the channel. Moreover there is great interest in energy conversion devices that convert heat into electricity or use electrical energy to pump heat. Our purpose here is (1) to describe the basic principles that must be obeyed by any model for energy conversion processes in order to comply with the laws of thermodynamics and (2) to convey the insights that nanodevices provide into the subtle issues of irreversibility that Boltzmann struggled with over a century ago when he constructed the first transport theory.This lecture is part 1 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, hosted/taped by NCN@Purdue, Maxwell\'s Demon, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsWed, 03 Sep 2008 00:28:08 +0000https://nanohub.org/site/resources/2008/08/05295/2008.07.17-l4a-datta.mp3Lecture 4B: Energy Exchange and Maxwell’s Demon
https://nanohub.org/resources/5272
Figure 4Objective: To incorporate distributed energy exchange processes into the previous models from lectures 1 through 3 which are based on a “Landauer-like picture” where the Joule heating associated with current flow occurs entirely in the two contacts.Although there is experimental evidence that this idealization is not too far from the truth in many nanodevices of today, dissipation generally occurs throughout the channel. Moreover there is great interest in energy conversion devices that convert heat into electricity or use electrical energy to pump heat. Our purpose here is (1) to describe the basic principles that must be obeyed by any model for energy conversion processes in order to comply with the laws of thermodynamics and (2) to convey the insights that nanodevices provide into the subtle issues of irreversibility that Boltzmann struggled with over a century ago when he constructed the first transport theory.This lecture is part 2 of 2.https://nanohub.org/site/resources/2008/08/05299/2008.07.17-l4b-datta.mp3Figure 4Objective: To incorporate distributed energy exchange processes into the previous models from lectures 1 through 3 which are based on a “Landauer-like picture” where the Joule heating associated with current flow occurs entirely in the two contacts.Although there is experimental evidence that this idealization is not too far from the truth in many nanodevices of today, dissipation generally occurs throughout the channel. Moreover there is great interest in energy conversion devices that convert heat into electricity or use electrical energy to pump heat. Our purpose here is (1) to describe the basic principles that must be obeyed by any model for energy conversion processes in order to comply with the laws of thermodynamics and (2) to convey the insights that nanodevices provide into the subtle issues of irreversibility that Boltzmann struggled with over a century ago when he constructed the first transport theory.This lecture is part 2 of 2.nocourse lecture, dev/funded by NCN@Purdue, from Purdue, hosted/taped by NCN@Purdue, Maxwell\'s Demon, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:04 +0000https://nanohub.org/site/resources/2008/08/05299/2008.07.17-l4b-datta.mp3Introduction: Nanoelectronics and the meaning of resistance
https://nanohub.org/resources/5210
This lecture provides a brief overview of the five-day short course whose purpose is to introduce a unified viewpoint for a wide variety of nanoscale electronic devices of great interest for all kinds of applications including switching, energy conversion and sensing. Our objective, however, is not to discuss specific devices or applications. Rather it is to convey the conceptual framework underlying the bottom-up approach which not only provides practical insights into the design of nanoscale devices, but also affords conceptual insights into the meaning of resistance and the essence of non-equilibrium phenomena in general.No prior knowledge of quantum mechanics or statistical mechanics is assumed; however, familiarity with matrix algebra will be helpful for some topics.https://nanohub.org/site/resources/2008/08/05254/2008.07.14-intro-datta.mp3This lecture provides a brief overview of the five-day short course whose purpose is to introduce a unified viewpoint for a wide variety of nanoscale electronic devices of great interest for all kinds of applications including switching, energy conversion and sensing. Our objective, however, is not to discuss specific devices or applications. Rather it is to convey the conceptual framework underlying the bottom-up approach which not only provides practical insights into the design of nanoscale devices, but also affords conceptual insights into the meaning of resistance and the essence of non-equilibrium phenomena in general.No prior knowledge of quantum mechanics or statistical mechanics is assumed; however, familiarity with matrix algebra will be helpful for some topics.nobottom up approach, course lecture, from Purdue, hosted/taped by NCN@Purdue, Maxwell\'s Demon, nanoelectronics, NEGF, quantum transport, transport/quantumSupriyo DattaSupriyo DattaOnline PresentationsThu, 21 Aug 2008 00:06:29 +0000https://nanohub.org/site/resources/2008/08/05254/2008.07.14-intro-datta.mp3