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1 Condensed Matter Journal Club WikiPage
2 Winter '09 Journal Club
- 2.1 Schedule
3 Autumn '08 Journal Club
- 3.1 Schedule
- 3.2 Main References
4 Previous Journal Clubs
5 Potential Future Topics
6 Other

Condensed Matter Journal Club WikiPage

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Winter '09 Journal Club

Topic: Strongly correlated systems
Official talks are Thursdays at 12:30 in C421
Practice talks are after colloquium on Mondays, ~5:15 in B417

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Schedule

1/14/09 -- Overview of Strongly Correlated Systems

Dima Pesin
Abstract: I will give a brief review of the topics we decided to cover this quarter. Some information on Fermi and Luttinger liquids, Wigner crystallization, Fractional Quantum Hall Effect, Mott insulators, and the Kondo problem will be included. The talk is supposed to give some flavor of the subjects to allow this quarter's speakers to pick those most interesting to them.

1/22/09 -- The Landau theory of the Fermi Liquid

Lefteris Kirkinis
Abstract; I will present the phenomenology of the Fermi Liquid theory: main assumptions, validity and calculation of

equilibrium properties: specific heat, compressibility and first sound, magnetic susceptibility. I will follow the derivations of Negele and Orland 'Quantum Many-Particle systems'. Vol 9 of Landau and Lifshitz 'Statistical Physics II' is also very clear. The following article by Abrikosov and Khalatnikov was suggested by Professor Thouless: The Theory of a Fermi Liquid- (The Properties of Liquid HE-3 at Low Temperature) Reports on Progress in Physics 22, 329-367, (1959)

1/29/09 -- Fermi Liquids (cont'd)

Alan (Yuan Lung ) Luo
Abstract: I will present the kinetic equation for the Fermi-liquid theory, and show some properties derived from the kinetic equations: collective modes like zero sound, spin-waves, and thermal/electrical conductivity. In the end I will scratch a little bit on the collision integral for various scattering mechanisms.

I'll follow the derivation from either Arbikosov's Fundamentals of the theory of solid or Vol 9 of Landau and Lifshitz 'Statistical Physics II'. Experimental evidence on the collective modes are in:

zero-sound: Phys. Rev. Lett. 17, 74 (1966), JEPT Lett. Vol. 50, (1989) spin-wave: Phys. Rev. Lett. 18, 283 (1967)

2/5/09 -- Wigner Crystals

Greg Putzel
Abstract:
References:

2/12/09 -- Mott Insulator Transition/Hubbard Model

Mat Steuck
Abstract: The Hubbard model improves upon the familiar tight-binding model of solid-state physics and it will allow us to qualitatively understand the Mott Insulator transition.
References: ? Metal-Insulator Transitions, Rev. Mod. Phys. 70, 1039 - 1263 (1998) ?

2/19/09 -- Luttinger Liquids 1

Dima Pesin
Abstract:
References:

2/26/09 -- Luttinger Liquids 2

Wei Chen
Abstract:
References:

3/5/09 -- Kondo Problem

Eric Deyo
Abstract:
References:

3/12/09 -- Last week of classes

Would be nice to have another talk here

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Autumn '08 Journal Club

Topic: Phase transitions and critical phenomena
Official talks are at 12:30 in C421
Practice talks are after colloquium on Mondays, ~5:15 in B417

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Schedule

10/1/08 -- Introduction/Mean Field Concepts

Mathew Steuck
Abstract - Today I'll be introducing phase transitions and critical phenomena by looking at what Weiss molecular mean field theory has to say about the Ising model and then briefly discussing the limitations of mean field theory.

There is a whole assortment of books that deal with phase transitions and critical phenomena, some references for today include Chapter 3 of Plischke and Birgerson's Equilibrium Statistical Physics and Chapter 4 of Chaikin and Lubensky's Principles of Condensed Matter Physics.

10/8/08 -- Landau Approach to Phase Transitions

Greg Putzel
Abstract - In today's journal club talk, I will continue our discussion of mean field theory by describing Landau's phenomenological approach to second order phase transitions. This will be illustrated using the Ising ferromagnet as an example. Extending this theory, à la Landau-Ginzburg, to situations where the order parameter varies in space, will allow us to find a mean-field expression for the correlation function. Finally I will use the correlation function to define the Ginzburg parameter, which gives a criterion for the self-consistency of mean field theory.

10/15/08 -- Introduction to the Renormalization Group

Lefteris Kirkinis
Abstract - I will obtain the exact solution to the 1-D Ising problem with periodic boundary conditons and obtain an expression for the free energy that scales with the correlation length \xi. Further introducing the scaling hypothesis and Kadanoff's assumption, I will introduce the RG to show how the coupling constants 'flow' in parameter space and obtain the same scaling for the the free energy as the one I obtained from the exact solution. Essentially I will cover p.361-3 and Ch 18 of K. Huang 'Statistical Mechanics'.

10/22/08 -- Scaling

Mathew Steuck
Abstract - I will be discussing the scaling hypothesis today and how it allows us to relate various scaling exponents to one another. I will explain how this is motivated with Kadanoff block spins and hopefully I will make it to hyperscaling relations. Most of this is in section 5.3 of Plischke and Bergerson and sections 5.4-5 of Chaikin and Lubensky.

10/29/08 -- Scaling (cont'd)

Mathew Steuck
Abstract - I will finish my talk from last week by discussing how the Kadanoff block picture gives a heuristic justification for scaling, discuss hyperscaling, and might briefly mention finite size scaling.

11/5/08 -- Momentum Space Renormalization

Eric Deyo
I will apply the Renormalization Group in momentum space to the n-vector model, and derive the renormalized Hamiltonian to first order in \epsilon = 4-d. I will basically present section 5.8 in Chaikin and Lubensky.

11/12/08 -- Percolation

Greg Putzel
Percolation is an example of a problem to which almost everything we have discussed this quarter can be applied. I will introduce the concept of percolation and define the important quantities and their critical exponents. Some of the critical exponents will be calculated in the case of percolation on the Bethe 'lattice', which corresponds to mean-field theory. Then I will discuss the scaling form of the distribution of cluster sizes. As in the case of thermal phase transitions, the scaling form leads to relations among the critical exponents.

11/19/08 -- Topic TBD

Wei Chen

11/26/08 -- Thanksgiving Eve, no journal club

12/02/08 (Notice this seminar is on a TUESDAY)-- The Berezinkii-Kosterlitz-Thouless (BKT) transition for the XY model.

Lefteris Kirkinis
Abstract - I will demonstrate the corellation function for high and low temperatures which will show the existence of a finite temperature phase transition. This was justified by BKT by the introduction of the concept of topological defects or vortices. At low temp the charges appear as tightly bound dipoles; in the high temperatures they dissociate forming a plasma. I will describe their behavior performing renormalization on the effective interaction between two external charges and discuss the separation the RG flows induce to the parameter (K=coupling, y_0 = fugacity) space. I will copy-paste the notes of Mehran-Kardar Topological Defects in the XY model,Renormalization Group for the Coulomb Gas where the original references also appear.

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