Condensed-matter/AMO Joint Seminars
Fall 2005
Tuesdays at 4 pm, 335 West Hall.


Organizer:Luming Duan



September 13
Ronald Walsworth (Harvard University),
Title: "". (CANCELED)


September 20 
Jennifer Ogilvie (University of Michigan)
Title: "New Directions in Multi-photon Microscopy".


September 27 
Zheng-Tian Lu (Argonne National Lab ? University of Chicago)
Title: "Atom Trap, Krypton-81, and Saharan Water"

Abstract: Since radiocarbon dating was first demonstrated in 1949, the field of trace analyses of long-lived cosmogenic isotopes has seen steady growth in both analytical methods and applicable isotopes. The impact of such analyses has reached a wide range of scientific and technological areas. A new method, named Atom Trap Trace Analysis (ATTA), was developed by our group and used to analyze 81Kr (t1/2 = 2.3?105 years, isotopic abundance ~ 1?10-12) in environmental samples. In this method, individual 81Kr atoms are selectively captured and detected with a laser-based atom trap. 81Kr is produced by cosmic rays in the upper atmosphere. It is the ideal tracer for dating ice and groundwater in the age range of 104106 years. As the first real-world application of ATTA, we have determined the mean residence time of the old groundwater in the Nubian Aquifer located underneath the Sahara Desert. Moreover, this method of capturing and probing atoms of rare isotopes is also applied to experiments that study exotic nuclear structure and test fundamental symmetries.



October 4 
Frank Verstraete (Caltech)
Title: "Strongly correlated quantum systems from the point of view of quantum 
information theory".


October 11 
Jason (T.-L.) Ho (Ohio State University)
Title: "Spinor Bose Condensate and Multi-Component Quantum Gases".


October 18 
Tony Leggett (UIUC), Nobel Laureate (2003).
Location: 340 West Hall
Title: "Ultracold Fermi alkali gases:Bose condensation meets Cooper pairing"

Abstract: After a brief review of the history of the so-called "BEC-BCS crossover 
problem",I describe the general features of the system of ultracold dilute
alkali gases which has permitted its realization over the last eighteen 
months; I comment on some of the experiments done on these systems and review 
some open questions.



October 25 
Brian DeMarco (UIUC)
Title: "Quantum Simulation using Ultra-cold Atoms". 


November 1
Richard Martin (UIUC)
Title: "Insulators, metals, and fractionalized states - Berry's
phases and the Luttinger theorem"

Abstract: Recent work has led to a new approach for understanding the differ-
ent states of condensed matter: insulators, metallic Fermi liquids, possible
non-Fermi-liquid states, and states with fractional quantum numbers - a
non-perturbative, topological approach involving Berry's phases. A central
quantity is the Luttinger theorem that the volume enclosed by the Fermi
surface is not changed by electron-electron interactions - a crucial matter for
issues such as whether or not it is possible to have a Mott insulator with no
broken symmetry such as antiferromagnetism or a Peierls distortion. The
new approach (for example, recent papers by M. Oshikawa) is based upon
topological arguments on the behavior of the quantum wavefunction as a
function of boundary conditions, that relate some of the most fundamental
concepts in physics, including the Aharonov-Bohm effect, the nature of the
insulating state, a generalized form of the Luttinger theorem, the fractional
quantum Hall effect, and other fractionalized states with topological order.
This talk will give an overview of the ideas and will focus upon simple ex-
amples relevant for current research, such as the fractionally-filled Hubbard
model.



November 8 
Alfonso Cebollada (Madrid University)
Title:"EPITAXY, MAGNETISM AND MAGNETOTRANSPORT OF Fe-MgO (001) HETEROSTRUCTURES"

Abstract: The aim of this talk is to give an overview of the results obtained during the last few years at the IMM concerning the epitaxy, magnetic and magnetotransport properties of different types of epitaxial Fe-MgO (001) nanostructures. With this purpose, we have first performed an extensive study on the epitaxy of Fe on MgO(001), as well as that of MgO on Fe(001). This has allowed us to fabricate ultrathin Fe(001) films, Fe/MgO/Fe trilayers and Fe/MgO superlattices on MgO, Si and GaAs (001) substrates with control of the structure and morphology at the atomic and nanometric level, extended to the  micrometric level by the use of lithography techniques. Once the influence of the different deposition parameters on the structure and morphology was understood and controlled, we embarked on a complete study on the different magnetic and magnetrotransport properties of these nanostructures. 
 



November 15 
Mark Dykman (Michigan State University)
Title: "Multiphoton antiresonance and quantum activation in driven oscillators"

Abstract: Resonantly modulated oscillators are predicted to display quantum 
effects, which have no analog in two-level systems. One of them is 
antiresonance of the coherent nonlinear response, in which the amplitude 
of forced vibrations of the oscillator displays a sharp minimum where 
the modulation frequency passes adiabatically through multiphoton 
resonance. The other is escape from metastable states of forced
vibrations via quantum diffusion over quasienergy levels. It is studied 
for resonantly and parametrically driven oscillator. In both cases, even 
for zero temperature, the diffusion rate is faster than the rate of 
dynamical tunneling between the states given that the latter is smaller 
than the relaxation rate. The effective activation energy of escape is a 
sharp function of temperature in the quantum regime. It displays a 
power-law dependence on the distance to the bifurcation value of the 
modulation amplitude or frequency.



November 22
Stephen Forrest (Princeton University)
Location: 340 West Hall
Title: "Singlets and Triplets and the Route to Electroluminescence
in Organic Materials"


November 29
Jelena Vuckovic (Stanford University)
Title: "Generation and manipulation of
classical and nonclassical light using photonic crystals".


December 6
Kathy Levin (University of Chicago) 
Title: "What can high Tc superconductors teach us about ultracold
atomic superfluids and vice versa?".


December 13
Jason Amini (Lawrence Berkely Labs) 
Title: "Progress Towards an Electron EDM Measurement using a Cold Atomic 
Fountain"

Abstract: Discovery of an electron electric dipole moment (EDM) in the 
range currently accessible by experiments would be firm evidence of physics 
beyond the Standard Model of particle physics.  I will present our work on 
measuring the electron EDM using a laser cooled/launched cesium 
fountain.  A fountain provides a number of benefits over a thermal beam 
apparatus.  I will discuss the advances needed to bridge the gap between 
our current results and the best limit..