Events Archive

Condensed Matter Seminar

Condensed Matter Seminar, Leonid Levitov , "Atomic collapse in graphene"

Mon, Nov 4, 2013, 1:15 pm to 2:30 pm
Since the discovery that electrons in graphene behave as massless Dirac fermions, the single-atom-thick material has become a fertile playground for testing exotic predictions of quantum electrodynamics, such as Klein tunneling and the fractional quantum Hall effect.

Condensed Matter Seminar, Yigal Meir, "Kondo Physics in Quantum Point Contacts"

Mon, Sep 30, 2013, 1:15 pm to 2:30 pm
Quantum point contacts (QPCs) are the basic building blocks of any mesoscopic structure, and display quantized conductance, reflecting the quantization of the number of transparent channels. An additional feature, coined the "0.7 anomaly", has been observed in almost all QPCs, and has been a subject of intensive debate in the last couple of...

Condensed Matter Seminar, Hong Ding, Institute of Physics, Chinese Academy of Sciences, "Probing iron-based superconductivity by photoelectrons"

Mon, Sep 9, 2013, 1:15 pm to 2:30 pm
Angle-resolved photoemission spectroscopy (ARPES) has been used extensively in studying electronic structure and superconducting gap of the iron-based superconductors (IBSCs). In this talk, I will present our ARPES results on the IBSCs, mainly focus on high-resolution measurements of the superconducting gap of many different IBSCs.

Condensed Matter Seminar, Xi Dai, "Topological phases in mix valence compounds"

Fri, Aug 30, 2013, 2:00 pm to 4:00 pm
In this talk, I will propose that the mix valence phenomena in some of the rare earth compounds will naturally lead to non-trivial topology in band structure.One of the typical example is SmB6, where the intermediate valence of Sm generates band inversion at the X point and the non-trivial Z2 index. Other than SmB6, YbB6 and YbB12 are both mix...

Quantum Sciences Seminar Series - David DiVincenzo, RWTH Aachen - "Engineering the Solid State Quantum Computer"

Mon, Jul 15, 2013, 1:30 pm to 2:30 pm
Progress on solid state qubits, particularly Josephson junction devices, now brings us to the possibility of planning a scalable, multi-qubit architecture.  While we can envision how the quantum part of device can be designed to effectively implement fault tolerant error correction, I will argue that, if implemented with present-day techniques,...

Condensed Matter Seminar, Liang Fu, MIT, From Topological Crystalline Insulator to Anderson Transition

Mon, May 13, 2013, 1:15 pm to 2:30 pm
Structure and symmetry play important roles in determining electronic properties of periodic solids. The interplay between crystalline symmetry and electronic topology leads to new phases of matter dubbed topological crystalline insulators, which possess protected surface states with unique and tunable electronic properties.

Condensed Matter LUNCH Seminar, Chen Fang, PU and Suyang Xu, PU

Wed, May 1, 2013, 12:00 pm to 1:00 pm
Chen Fang will discuss Crystalline Topological Insulators SuYang Xu will discuss Protected & Broken Symmetries in TIs

Special Condensed Matter Seminar, Kai Sun, U of Michigan at Ann Arbor, Kondo insulators: insulator, metal or topological insulator?

Tue, Apr 30, 2013, 3:30 pm to 5:00 pm
In the last few decades, various puzzles have emerged in the study of strongly-correlated materials. In a family of strongly-correlated insulators, known as Kondo insulators, one such long-standing puzzle has remained open for over 40 years.

Condensed Matter Seminar - Jeremy Levy, University of Pittsburgh, Oxide Nanoelectronics On Demand

Mon, Apr 29, 2013, 1:15 pm to 2:30 pm
Electronic confinement at nanoscale dimensions remains a central means of science and technology. I will describe a novel method for producing electronic nanostructures at the interface between two normally insulating oxides, LaAlO3 and SrTiO3.

Mon, Apr 22, 2013, 1:15 pm to Mon, Apr 15, 2013, 2:30 pm


Condensed Matter Seminar, Oleg Tchernyshyov, Z_2 spin liquid in the Heisenberg antiferromagnet on kagome

Mon, Apr 22, 2013, 1:15 pm to 2:30 pm
A spin liquid is a hypothetical quantum ground state of a frustrated Heisenberg magnet conjectured by P.W. Anderson in the 1970s. Its distinguishing features are (1) a lack of magnetic order and (2) a degeneracy that depends on the topology of the system.

Condensed Matter Seminar, Young S. Lee, MIT, Two faces of the kagomé lattice: quantum spin liquids and topological flat bands

Mon, Apr 15, 2013, 1:15 pm to 2:30 pm
I will describe experimental studies of new states of magnetism on the S=1/2 kagomé lattice. In particular, I will discuss results on two materials: one with antiferromagnetic exchange (herbertsmithite) and one with ferromagnetic exchange (Cu(1,3-bdc)).

Condensed Matter Seminar - Philip Kim, Columbia University - Bloch, Landau, and Dirac: Hofstadter’s Butterfly in Graphene

Mon, Apr 8, 2013, 1:15 pm to 2:30 pm
Electrons moving in a periodic electric potential form Bloch energy bands where the mass of electrons are effectively changed. In a strong magnetic field, the cyclotron orbits of free electrons are quantized and Landau levels forms with a massive degeneracy within.

Condensed Matter Seminar - Andrew Sachrajda, The National Research Council - Coherent Behaviour in a Triple Quantum Dot Circuit

Mon, Mar 25, 2013, 1:15 pm to 2:30 pm
In this talk I will describe our experimental investigations of an AlGaAs/GaAs based triple quantum dot circuit and their comparison with theoretical models. We are able to employ both quantum transport and charge detection down to single electron/spin occupation and employ many of the pulsing techniques developed previously for two dot circuits.

Special Condensed Matter Seminar - Ville Lahtinen - Condensate-induced transitions and critical spin chains

Fri, Mar 15, 2013, 1:15 pm to 2:30 pm
We show that the framework of condensate-induced transitions between two-dimensional topological phases can be used to relate one-dimensional spin models at their critical points.

PCTS/Condensed Matter Seminar - Salvatore R. Manmana, Goettingen University - Far-from-Equilibrium Quantum Magnetism with Ultracold Polar Molecules

Thu, Mar 14, 2013, 1:15 pm to 2:30 pm
Recent theory has indicated how to emulate tunable models of quantum magnetism with ultracold polar molecules.

Special Condensed Matter Seminar-Roman Lutchyn, Microsoft Sta. Q, UC, SB - Majorana zero-energy modes in semiconductor/superconductor heterostructures

Wed, Mar 13, 2013, 1:15 pm to 2:30 pm
The exploration of topological phases of matter is one of the main challenges in condensed matter physics. Among the exciting recent developments in this direction are the discoveries of new phases of matter with many intriguing properties, such as topological insulators and superconductors.

Condensed Matter Seminar - Collin Broholm, The Johns Hopkins University - "Continuum Excitations in Crystalline Magnets"

Mon, Mar 4, 2013, 1:15 pm to 2:30 pm
I present inelastic neutron scattering data from one- two- and three-dimensional insulating magnetic materials at low temperatures that do not display a coherent resonant mode of excitation. Instead, momentum resolved spectra take the form of bounded continua. I interpret the spectra as evidence for fractionalization of a spin flip into distinct...

Condensed Matter Seminar - Juerg Froehlich, ETH Zurich & IAS, Princeton - Gauge Theory and Topological Phases of Matter

Mon, Feb 25, 2013, 1:15 pm to 2:30 pm
We study a general class of systems of condensed matter including electron liquids and atom gases. Thanks to the U(1)- and SU(2)- gauge invariance of the quantum theory of such systems, one may study their response to coupling the electric current to a vector potential and the spin current to an SU(2)- gauge field.

Condensed Matter Seminar- Johnpierre Paglione, Univ of Maryland-Separation of magnetism and superconductivity in rare earth-doped CaFe2As2 by pressure

Mon, Feb 11, 2013, 1:15 pm to 2:30 pm
Traces of a high-Tc superconducting phase with transition temperatures approaching 50 K have been stabilized by the substitution of light rare earths for Ca atoms in the iron-pnictide material CaFe2As2 [*].

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