September 5, 2014 (Friday) 4:00-5:00p.m. Small Hall 110Speaker: Dr. Predrag Nikolic, GMU
Host: Prof. Enrico Rossi
Title: The rise of topological quantum entanglement
Abstract: Entanglement is at the heart of quantum mechanics, the fundamental theory of our world. Yet, it is hardly ever seen in macroscopic collections of particles. We presently know of only one real system that is macroscopically entangled in a non-trivial way beyond any doubt. This is the two-dimensional electron gas in a magnetic field strong enough to produce fractional quantum Hall effect. Several other material families may also realize macroscopically entangled quantum states of strongly interacting electrons. This talk will be devoted to one such family, known as "topological insulators" (TIs), which recently became a world-wide research focus. More specifically, samarium hexaboride (SmB6) and its subfamily of Kondo (heavy fermion) insulators are the first promising candidates for strongly correlated TIs. I will present a neutron scattering experiment combined with field-theory calculations that indeed paint SmB6 as a correlated topological material. Then, I will discuss the rich physics of exotic symmetry breaking and electron fractionalization that one can anticipate in Kondo TIs. With some luck, these and similar materials may provide a new playground for exploring fundamental phenomena in nature, and perhaps even a new setting for topological quantum computation.
September 19, 2014 (Friday) 4:00-5:00p.m. Small Hall 110Speaker: Carl Carlson, William & Mary
Host: Prof. E. Rossi
Title: The Proton Radius Puzzle
September 26, 2014 (Friday) 4:00-5:00p.m. Small Hall 111
Speaker: Prof. Michael Kohl, Hampton University
Host: Prof. C. Perdrisat
Title: The proton radius puzzle - how can it be resolved?
Abstract: The proton is not an elementary particle, it has a substructure governed by quarks and gluons. The spatial extensions of the electric charge and magnetization determine the size of the proton and its response to electromagnetic interaction. Recently, contradicting observations have challenged our understanding of the proton. The disagreement between proton radius determinations from high-precision muonic hydrogen spectroscopy and numerous atomic hydrogen and electron scattering measurements has become known as the proton radius puzzle, which has received much attention even in public media. The puzzle has a variety of possible resolutions, including physics beyond the Standard Model, missing conventional physics, and errors or underestimated uncertainties in the extraction of the radius from the data. I will discuss ways that will eventually help to resolve the puzzle.
October 3, 2014 (Friday) 4:00-5:00p.m. Small Hall 111
Speaker: Prof. James Eckstein, University of Illinois-Urbana
Host: Prof. M. Qazilbash
Title: The Superconducting Proximity Effect
Abstract: The superconducting proximity effect arises when a superconductor “shares” its pairs with a nonsuperconducting layer with which it is in good contact. It has been studied in many experiments, sometimes showing unexpected behavior. Renewed interest in proximity coupled superconductivity has arisen due to experimental results that suggest Majorana Fermions can form in devices that include topological materials, such as topological insulators and devices made from certain semiconductors such as InAs. I will review superconductivity and the proximity effect, and then discuss some recent experiments in which proximity induced changes in normal state properties of both semiconductors and topological insulators have been measured.
October 10, 2014 (Friday) 4:00-5:00p.m. Small Hall 111Speaker: Julia M. Phillips, Sandia National Laboratory
Host: Prof. P. Vahle
Title: Research and Technologies for National Security: A perspective from a national security laboratory
Abstract: Sandia National Laboratories is the Nation’s largest national security laboratory. The mission of the laboratory to deliver engineered solutions for national security needs is built on a broad and deep base of scientific research and expertise. I will motivate the research at Sandia by describing the Laboratories’ historical evolution, research accomplishments and priorities, and current mission. I will then discuss some of the exciting research challenges that the Laboratories are pursuing, including topics such as Beyond Moore Computing, First to High Yield Fusion, Engineering of Materials Reliability, and Science & Engineering of Quantum Information Systems.
October 30, 2014 (Friday) 4:00-5:00p.m. Small Hall 111 (Special Colloquium)
Host: Prof. Ale Lukaszew
Title: Using Light to Probe Ultrafast Dynamics
induced insulator-metal transition in novel materials such as VO2 and NbO2. Recently we have configured a new setup to make these measurements in the Ultrafast Lab of Prof. Lukaszew and I will present some of our preliminary experimental results. These types of materials show great promise for passive light control and innovative all-optical sensing and switching. The nature of the ultrafast optical response of these materials though is not yet understood, and these types of measurements will be a key piece for solving this puzzle.
October 31, 2014 (Friday) 4:00-5:00p.m. Small Hall 111
Host: Prof. S. Aubin
Title: Atoms coupled to a superconducting circuit, a progress report.
November 7, 2014 (Friday) 4:00-5:00p.m. Small Hall 111Speaker: Gianpolo Carosi, LLNL
Host: Prof. A. Walker-Loud
Title: The Hunt for Dark Matter Axions
November 10, 2014 (Monday) 4:00-5:00p.m. Small Hall 110Speaker: Dan Millison, P.E., P.G./Transcendergy, L.L.C.
Host: Physics Chair, Gene Tracy
Title: Saving the Forest and the Trees: A Conceptual Model of Sustainable Coal
As most energy policy-makers believe that leaving coal in the ground is an unrealistic scenario for the foreseeable future, carbon capture and storage (CCS) has attracted significant research and development in an attempt to achieve some semblance of carbon neutrality. Commercially viable-CCS presents a potential moral hazard: “solving” the CO2 disposal problem will encourage greater use of coal, without addressing the upstream environmental and social impacts of coal mining, transport, and downstream waste disposal. “Clean coal” as currently envisioned – supercritical power with CCS bolted on – is not sustainable. CCS as end-of-pipe disposal is a non-starter in the absence of a robust regulatory framework for waste management including carbon pricing.
Bypassing the dual challenges of making coal “too expensive” or making low-carbon energy “too cheap to meter,” there is an intermediate solution to render coal more sustainable. Sustainable coal - not to be confused with “clean coal” – is possible by combining underground coal gasification (UCG, with the produced gas used in combined-cycle gas turbine power plants or other off-the-shelf systems including conversion to liquids) with carbon capture, reuse, and storage (CCR, preferably via carbonate mineralization or other utilization not involving additional hydrocarbon production). This end-to-end system is necessary to close the sustainability loop.
UCG is not a new technology, having been deployed in the former Soviet Union more than 60 years ago. There are several commercial UCG operations worldwide today, but it is not well-known even among energy specialists. UCG can remove most of the negative externalities associated with coal mining, transport, and conventional pollutant management. CCR would provide a positive market driver in place of a price on carbon. A commercially viable CCR system would also enable more sustainable exploitation of non-conventional gas resources (e.g., shale gas). An end-to-end system would facilitate the convergence of energy security and climate change objectives globally and particularly in developing countries which may rely increasingly on imported coal.
In the US, UCG offers the prospect of transforming the coal mining industry to a high-value-added sector supporting next-generation power plants and coal-to-liquids production, at the same time facilitating exports of natural gas.
November 14, 2014 (Friday) 4:00-5:00p.m. Small Hall 111Speaker: Dr. Vincent Liu, University of Pittsburgh
Host: Prof. Enrico Rossi
Title: Topological orbital bands: from optical lattices to oxide interfaces
November 21, 2014 (Friday) 4:00-5:00p.m. Small Hall 111
Host: Prof. Wouter Deconinck
Title: The E-906/SeaQuest Experiment at Fermilab
The E-906/SeaQuest experiment at Fermilab continues a series of Drell-Yan measurements to explore the antiquark content of the nucleon and to study the modifications to nucleon structure when the nucleon is embedded into a nuclei. To extend existing measurements to larger values of Bjorken-x - the momentum fraction of a quark within the nucleon - a 120 GeV proton beam extracted from Fermilab’s main injector is used, resulting in 50 times more luminosity than previous experiments and enabling access to values of x up to 0.9.
An overview will be presented of the key physics goals of the SeaQuest collaboration: These include investigation of the dramatic dbar/ubar flavor asymmetry in the nucleon sea and its behavior at high x; study of the EMC effect in Drell-Yan scattering and the unexpected absence of any antiquark excess in existing data; and measurements of the angular dependence of the Drell-Yan process, sensitive to spin-orbit correlations within the nucleon. Updates to the SeaQuest experiment with polarized beam (E-1027) and target (E-1039) will allow us to study the quarks' spin-orbit correlations within the nucleon and to provide complementary information to existing data from DIS. The talk will conclude with a status report on the ongoing data taking and analysis of this new experiment.