# Events Archive

## Condensed Matter Seminar

### Special Condensed Matter Seminar, Jerome Dubail, "Fractional Quantum Hall Effect: from bulk model wave functions to the edge theory"

Wed, Mar 28, 2012, 3:15 pm to 4:45 pm
Since the seminal contribution of Laughlin in the early 1980s, a large part of the theoretical work on the FQHE has consisted in cooking up new model wave functions for different filling fractions.

### Special Condensed Matter Seminar, Benoit Estienne, "D-Algebra Structure of Topological Insulators"

Tue, Mar 27, 2012, 2:45 pm to 4:00 pm
In the quantum Hall effect, the density operators at different wave-vectors generally do not commute and give rise to the Girvin MacDonald Plazmann (GMP) algebra with important consequences such as ground-state center of mass degeneracy at fractional filling fraction, and W_{1 + \infty} symmetry of the filled Landau levels.

### Condensed Matter Seminar - Umesh Vazirani, Berkeley, "Testing quantum systems "

Mon, Mar 26, 2012, 1:15 pm to 2:30 pm
Quantum computation teaches us that general quantum quantum systems of n particles exhibit complexity that scales exponentially in n. Can we test whether the output of such a system is consistent with quantum mechanics? For example, is it possible to test whether a claimed implementation of a quantum computer is "really quantum". The difficulty...

### Special Condensed Matter Seminar, Chen Fang, “Topological Insulators and Semimetals with Point Group Symmetries”

Tue, Mar 13, 2012, 2:45 pm to Mon, Mar 12, 2012, 4:00 pm
In this talk we will first discuss topological band insulators with crystallographic point group symmetries (PGS), extending the regime of topological phases to include systems beyond those having time-reversal symmetry. In principle, any discrete symmetry gives rise to a topological classification of insulators indexed by quantum numbers...

### Special Condensed Matter Seminar, Chen Fang, “Topological Insulators and Semimetals with Point Group Symmetries”

Tue, Mar 13, 2012, 2:45 pm to 4:00 pm
In this talk we will first discuss topological band insulators with crystallographic point group symmetries (PGS), extending the regime of topological phases to include systems beyond those having time-reversal symmetry. In principle, any discrete symmetry gives rise to a topological classification of insulators indexed by quantum numbers...

### CMP Seminar - Tianheng Han - MIT - The Search For Quantum Spin Liquids

Thu, Jan 12, 2012, 3:15 pm to 4:15 pm
The experimental realization of a quantum spin liquid ground state in two-dimensions-a new form of matter with no conventional broken symmetry-has been under intensive investigations for decades. Recently, this novel state has likely been discovered.

### Condensed Matter Seminar, Emanuele Dalla Torre, "Non-equilibrium quantum critical states: a real-time RG approach"

Mon, Dec 12, 2011, 1:15 pm to 2:30 pm
Abstract: Equilibrium thermal noise is known to destroy the scale invariance of quantum critical points, through the introduction of a finite thermal length. What are the effects of non-equilibrium time-dependent noise?

### Special Condensed Matter Seminar, Ville Lehtinen, "Topological liquid nucleation induced by vortex-vortex interactions in Kitaev’s honeycomb model"

Mon, Nov 28, 2011, 1:15 pm to 2:30 pm
Abstract: We provide a microscopic understanding of the nucleation of topological quantum liquids for interacting non-Abelian anyons by making an explicit connection between the microscopics of the pairwise interactions – typically showing RKKY-type behavior oscillating in sign, but decaying exponentially with distance – and the nature of the...

### Condensed Matter Seminar, Lu Li, "Magnetism of LaAlO3/SrTiO3 Heterostructure Interface"

Mon, Nov 21, 2011, 1:15 pm to 2:45 pm
Abstract: The LaAlO3/SrTiO3 heterostructure is a potential candidate for a high mobility two-dimensional electron system with novel electronic and magnetic properties. Though LaAlO3 and SrTiO3 are both large-gap band insulators, the interface is conductive, and even superconducting below 200 mK.

### Condensed Matter Seminar, Tk Lee, "Recent progress on the variational approach to understand high temperature superconductors".

Mon, Oct 31, 2011, 1:15 pm to 2:30 pm
Abstract: Since the pioneering proposal by Anderson that the superconducting state of high-Tc cuprates can be described by the resonanting-valence-bond (RVB) state, a number of important results to support the idea were obtained by using the variational approach to study the t-J model. However, two major issues were not addressed at the...

### Special CMS, Fiona Burnell Building fractional topological insulators

Fri, Sep 30, 2011, 1:30 pm to 6:00 pm
Abstract: Time-reversal invariant band insulators can be separated into two categories: ordinary' insulators and topological' insulators. Topological band insulators have low-energy edge modes that cannot be gapped without violating time-reversal symmetry, while ordinary insulators do not.

### Special CMS Dr. Hugo Dil, Paul Sherrer Inst. "Spin texture manipulation in systems with large spin-obit interaction."

Thu, Jul 28, 2011, 2:00 pm to 6:00 pm
Abstract: The COPHEE end station at the Swiss Light Source can provide the three spatial components of the expectation value of the spin polarization. Combined with our vectorial analysis method this allows us to determine the spin polarization vector for any region in momentum space.

### Condensed Matter Seminar

Mon, Jul 18, 2011, 1:30 pm to 6:30 pm
Abstract: The fundamental collective degree of freedom of fractional quantum Hall states is identified as a unimodular two-dimensional spatial metric that characterizes the local shape of the correlations of the incompressible fluid. Its quantum fluctuations are controlled by a topologically-quantizedâguiding-center spinâ

### Jainendra Jain TBA

Mon, May 2, 2011, 1:15 pm to Mon, Feb 28, 2011, 6:00 pm
Abstract: TBA

### Xiao-Liang Qi Title: TBA

Mon, Mar 14, 2011, 1:15 pm to 6:00 pm
Abstract: TBA

### Shinsei Ryu, Berkeley

Mon, Mar 7, 2011, 1:15 pm to 6:00 pm

### Sir Michael Berry, Hamiltonian Lecturer

Mon, Feb 21, 2011, 1:15 pm to 6:00 pm

### Sir Michael Berry, Hamiltonian Lecturer

Mon, Feb 14, 2011, 1:15 pm to 6:00 pm