Spring 2017: Colloquium Series

Talks are usually scheduled on Thursdays during common hour (12:50 – 1:50 PM) in Room N304 of the Science and Engineering Building, unless otherwise indicated. Lunch is served starting at 12:20PM. All are welcome!


Thursday March 30, 2017

Fractals and the Drip Paintings of Jackson Pollock

Katherine Brown (Jones-Smith)
Physics Department, Hamilton College

In the late 1990s, a group of physicists analyzed some of the most famous drip paintings by the celebrated Abstract Expressionist painter Jackson Pollock. Assuming Pollock underwent a particular type of chaotic motion, they found that every layer of every painting they analyzed possessed the same fractal characteristics. From this they conjectured that Pollock was able to create a unique fractal ‘signature’ in his work, and that fractal analysis could therefore be used as an authentication tool in paintings of disputed origin. It turns out that this hypothesis of ‘Fractal Expressionism’ is flawed in several important ways. I will present an account of the techniques used in fractal analysis and the pitfalls which ensue from applying them to Pollock’s drip paintings. I will also discuss several new findings from the realm of fractal mathematics which were motivated by this work.


Thursday April 6, 2017

Excitons in Small Molecules Crystalline Thin Films

Madalina Furis
Physics Department, University of Vermont

Organic electronics, an interdisciplinary research area traditionally more connected to organic synthetic chemistry and polymer science than condensed matter physics, is currently undergoing a major transformation. The advent of high mobility small molecule semiconductors and new avenues for scalable thin film and device fabrication introduce a new paradigm in the way we think about the future of electronics.

At the University of Vermont my research group focuses on exploring crystalline organic semiconducting thin films using condensed matter experimental approaches (such as low temperature, polarization-resolved, ultrafast spectroscopy) on a quest for signatures of many-body physics in these systems. Recent results include: i) the observation of a low temperature coherent exciton state [1] ii) the surprising discovery of excitonic states localized at the grain boundary that may provide new insight on exciton diffusion in these systems,[2]

  1. Rawat, N., et al. J.Phys. Chem. Lett. 2015, 6(10), 1834-1840.
  2. Pan, Z., et al. Nat.Commun. 2015, 6.

Email Contact: Madalina.Furis@uvm.edu


Thursday April 13, 2017

Topology of the Universe: Hearing the Shape of a drum

Eric Greenwood
Geology and Physics Department, University of Southern Indiana

Observationally, we know that the universe is locally flat. This does not tell us, however, the overall shape of the universe; that is, it does not tell us anything about the global shape of the universe (topology). There are many different global shapes which yield the same local shape. The question of the structure and size of the universe is both an intellectually interesting and an important question in modern cosmology since the answer to these questions could give us insight into the ultimate fate of our universe. Additionally, knowledge of the shape and size of the universe will give us information about the metric of the universe, which has many implications such as implications toward quantum gravity. In this talk, we will investigate how to reconstruct the topology of the universe using the spectrum of eigen modes dictated by a particular topology; that is, we will investigate how to “hear the shape of a drum.”


Thursday April 20, 2017

The God Quasiparticle: the Plasmon and Protein Spectroscopy

Shyamsunder Erramilli
Department of Physics, Boston University

How do we get an infrared vibrational spectrum of a protein molecule at attomole concentrations at room temperature? The absorption cross-section of the molecule is ~ 10-21 cm2, about 6 orders of magnitude smaller than methods based on fluorescent labels. To enhance the probability of absorption, we can exploit the very first quantum quasi-particle that was ever discovered, the plasmon. Nanoantenna can be used to enhance selected vibrational bands. Recently a collaboration with Dal Negro has used fractal structures for enhancing multiple infrared absorption band in the mid-infrared “fingerprint” region. The interaction between the phonon in the protein and the plasmon leads to extraordinary new phenomena. Plasmon-enhanced infrared spectroscopy has the potential to study changes in protein conformation without using labels, with discoveries of great interest to the Biological Physics community as well as the Biomedical community.


Thursday April 27, 2017

A Career in Big Data: Physics and the Software Industry

Jason Slaunwhite ’04

During this talk I will share a few short stories from my career in Big Data. After graduating from Union in 2004, I did research in High Energy Particle Physics and went on work at the CERN laboratory in Switzerland. I have continued to work with Big Data as a software developer for an analytic database company. I hope that by sharing a few of my experiences with current physics majors, I can provide some perspective on the different opportunities that they may consider pursuing after graduation.


Thursday May 4, 2017

 

 


Thursday May 11, 2017

Steinmetz Symposium Week


Thursday May 18, 2017

Searching for the Sources of the Highest-Energy Cosmic Neutrinos

Colin Turley
Department of Physics, Penn State

We present two archival analyses attempting to identify gamma-ray counterparts to the public neutrino data from the IceCube neutrino observatory. Our first analysis is a targeted search for correlated neutrino and gamma-ray emission from six bright northern blazars. These blazars were subject to long-term monitoring campaigns by the VERITAS TeV gamma-ray observatory. We use the publicly-available VERITAS light-curves to identify periods of excess and flaring emission to serve as active temporal windows in a search for an excess of neutrinos, relative to Poisson fluctuations of the near-isotropic atmospheric neutrino background. Our second analysis searches for an excess of statistically significant coincidences between Ice-Cube neutrinos from the 40 and 59 string configurations and gamma-rays detected by the Fermi LAT satellite. Both analyses are examples of more general multi-messenger studies that the Astrophysical Multi-messenger Observatory Network (AMON) aims to perform. For both analyses, we present the component neutrino and gamma-ray datasets, the statistical approaches, the results of the analyses, and future extensions to these studies.


Thursday May 25, 2017

Optics and electronics in two-dimensional (2D) materials

Swastik Kar
Department of Physics, Northeastern University

In the past decade, atomically-thin, layered or 2D materials have generated enormous interest within the science and engineering community. The unique nature of charge carriers, often experiencing strong interactions within a 2D confinement has led to spectacular new physical observations. At the same time, remarkable new applications have been shown to be possible within these materials with atomically-thin form-factors. This talk will outline some of the recent developments in our research group in the synthesis of 2D materials and their heterostructures, characterizations of their novel optical and electronic properties, and development of applications in the nanoelectronics, optoelectronics, sensing, detection, actuation, energy, and other areas. The aim will be to motivate how the novel physics of quantum matter can be potentially harnessed to develop applications with unprecedented performances.


Thursday June 1, 2017

Sigma Pi Sigma Induction


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