
CIFAR Nanoelectronics Summer School 2007
June 2729, 2007, University of British Columbia

Ian Affleck, University of British Columbia
Title: The Kondo effect in quantum dots and in atoms on surfaces

A spin1/2 impurity in a metal or a quantum dot on a semiconductor
interface can lead to some simple but interesting many body physics in
which the impurity spin acts freely at T >> T_K but forms a spin singlet
with a conduction electron at T<<T_K where T_K is called the Kondo
temperature.
In these lectures I will:
 Review the renormalization group picture and phenomenology of the Kondo
effect in metals
 Discuss the Kondo effect in quantum dots
 Introduce nonFermi liquid Kondo effects seen in double quantum dots

Supriyo Datta, Purdue University
Title: Nanodevices and Maxwell's Demon 
Maxwell invented his famous demon to illustrate the subtleties of the second law of thermodynamics and his conjecture has inspired much discussion ever since. Technology has now reached a point where it is possible to build an electronic Maxwell’s demon that can be interposed between the two contacts (source and drain) of a nanoscale conductor (the channel) to allow electrons to flow preferentially in one direction so that a current will flow in the external circuit even without any external source of power.
In this series of three talks I will use this device to illustrate the fundamental role of “contacts” and “demons” in transport and energy conversion. The discussion is kept at an academic level steering clear of real world details, but the illustrative devices we use are very much within the capabilities of presentday technology. Indeed the Maxwell’s demon device itself is very similar to the pentalayer spintorque device which has been studied by a number of groups though we are not aware of any attempt to use it as a nanoscale heat engine or as a refrigerator as proposed here.
The objective, however, is not to evaluate possible practical applications. Rather it is to introduce a transparent model for quantum transport far from equilibrium based on a combination of the Landauer approach with the nonequilibrium Green function (NEGF) method, which is now being widely used in the analysis and design of nanoscale devices. It provides a unified description for all kinds of devices from molecular conductors to carbon nanotubes to silicon transistors covering different transport regimes from the ballistic to the diffusive limit. But most importantly, it leads to a unique view of current flow that is very different from the conventional viewpoint.
References:
 S.Datta, Nanodevices and Maxwell’s demon, to appear in the Proceedings of the Third ASI International Workshop on Nano Science & Technology, Ed. Z.K. Tang, Taylor & Francis (2007), arXiv:condmat/0704.1623.
 S.Datta, Concepts of Quantum Transport, a series of video lectures, http://www.nanohub.org/courses/cqt.
 S.Datta, Quantum Transport: Atom to Transistor, Cambridge (2005).

Joshua Folk, University of British Columbia
Title: Measurement of single spins in solid state systems 
The first demonstration of electron spin detection in solid state
materials came with the advent of electron spin resonance in the
1940's. Electron spin resonance (ESR) is an ensemble
measurement, sensitive to the minute magnetic moment of an electron
spin only when integrated over 10^9 or more electrons. Over the past 5 years, a variety of experimental techniques have been developed
that push the detection limit down to the single electron level.
These efforts have been motivated in part by aspirations of quantum
information processing, and in part by a more fundamental interest in
spin decoherence mechanisms and interactions with the spin degree of
freedom in a solid state material. This series of seminars will
present an overview of these developments, their motivations, and an
outlook for the future.

Hong Guo, Center for the Physics of Materials and Department of Physics, University McGill
Title: Computational NanoElectronics

One of the most important branches of nanotechnology research is the
nanoelectronics. Nanoelectronic devices operate by the principle of quantum
mechanics and device properties are closely related to the atomic structure
of the system. It has been a theoretical challenge to calculate device
characteristics including relevant microscopic details of the device
structure in the nonequilibrium and quantum regime.
In these lectures, I will review the present status of nanoelectronic device
theory, the existing theoretical and numerical challenges, and some important
problems of nanoelectronics. I will then introduce and discuss various
approaches for calculating quantum transport properties of coherent quantum
structures. This discussion leads to the introduction of a formalism where
density functional theory (DFT) is carried out within the Keldysh
nonequilibrium Green's function (NEGF) framework. We demonstrate that the
NEGFDFT formalism allows quantitative calculations of nonlinear and
nonequilibrium charge and spin transport properties of various nanoscale
conductors without involving any phenomenological parameter. The detailed
theoretical background of the NEGFDFT formalism as well as its numerical
implementation will be presented. Quantitative comparisons to measured data
on various nanoelectronic devices will be made. I will then go through
examples of quantum transport through nanoscale devices based on the NEGFDFT
analysis: resistance of atomic and molecular wires, nanoscale spintronics,
field effects, STM image simluations, molecular vibrational spectrum during
current flow, nonequilibrium electronphonon coupling strength, inelastic
current, MRAM modeling, current induced magnetic moment reversal, graphene
electronics and various ideas of novel quantum devices.
The NEGFDFT formalism is most conveniently carried out for device simulations
in the steadystate within a mean field manner. Extensions and improvements
are necessary for situations of transient transport and strong correlation.
I will discuss some efforts in these directions and provide a outlook on
computational nanoelectronics.


Steven Bennett 
Full counting statistics in nanoelectromechanical systems 
Sarah Burke 
Dewetting in molecule on insulator systems: two prototypical examples 
Ricky Chu 
Nanoscale Hall probes: fabrication of magnetic sensors 
Fernando Delgado 
Spin Properties of the lateral triple quantum dot molecule in the presence of a magnetic field 
Shawn Fostner 
Controlled deposition of metal wires and contacts on KBr using nanostencils and surface structures 
Sergey Frolov 
Nonlocal spin and charge effects in twodimensional electron gas nanostructures 
Till Hagedorn + Mehdi El Ouali 
Simultaneous STM/AFM measurements with defined tips  understanding interactions at the atomic scale 
Hanifa Jalali 

Jesse Maassen 
Dephasing effect in ab initio modeling of a benzene molecule with aluminium leads 
Dylan McGuire 

Chris Payette 
Two and Three Energy Level Mixing Effects in Vertically Coupled Quantum Dots 
Adam Schneider 
Coherent Transport in Triple Quantum Dots 
Manuel Smeu 
Calculations of Electron Transport through Substituted Benzenes 
Vincent TabardCossa + Dhruti Trivedi 

Lara Thompson 

Xin Zhang 
New Lithography methods for fabricating structures of micro and nanoelectronics 

