Colloquium: Winter 2015 (Preparation Page)

Committee: Luca Grandi, Young-Kee Kim (chair), Dam Son, David Schuster

Colloquium at 4pm, followed by a reception (KPTC 206)

January 8, 2015
  1. Title: Entering the cauldron of climate change: Science and politics
  2. Speaker: Bob Rosner, University of Chicago
  3. Abstract: I will discuss how the Panel on Public Affairs (POPA) of the American Physics Society has dealt with the Society’s statement on climate change over the past two years. While the APS has not come to a final decision as yet, we do have a very clear understanding of where the science is - but a poor understanding of how to best explain this understanding to a highly politicized public.
  4. Faculty Host: Young-Kee Kim
January 15, 2015
  1. Title: Particle Physics after the Higgs
  2. Speaker: Marcela Carena, University of Chicago
  3. Abstract: The discovery of a Higgs Boson at the Large Hadron Collider (LHC) at CERN, marks the beginning of a new journey to understand the quantum nature of the vacuum, and the origins of matter and dark matter in our universe. Scrutinizing the basic properties of the Higgs Boson and its possible close relatives may shed light into these and other mysteries. Coming LHC data could distinguish models in which the Higgs is a composite state from those advocating the existence of an enhanced symmetry of nature, called Supersymmetry. Future experiments will explore connections between the Higgs boson, dark matter, baryogenesis and neutrinos.
  4. Faculty Host: LianTao Wang
January 22, 2015
  1. Title: Physics and Cosmology with the Cosmic Microwave Background
  2. Speaker: John Carlstrom, University of Chicago
  3. Abstract: The study of the cosmic microwave background (CMB) has driven spectacular advances in our understanding the origin, make up and evolution of our universe. We now have a standard cosmological model, ΛCDM, that fits all the cosmological data with only six parameters, although there are some tensions that may hint at that cracks in the model. Far from being the last word in cosmology, the model points to exciting times ahead using the CMB to explore new physics, i.e., inflation, dark matter, dark energy, neutrino masses and possible extra relativistic species, or dark radiation. This talk will review the current status and near term plans for CMB measurements, with emphasis on the South Pole Telescope, and discuss the plans for the next generation experimental program, CMB-S4.
  4. Faculty Host: Michael Turner
January 29, 2015
  1. Title: Urban Light
  2. Speaker: James Carpenter, James Carpenter Design Associates
  3. Abstract: In an ever expanding urban context, electrical light is suppressing our ability to experience light originating from our solar system, galaxy and beyond. Day and night, natural light simultaneously provides access to the unique specificity of place and the vast reaches of our imagination and dreams. "Urban Light" will explore light phenomena and the potential for a design approach founded on an understanding of these phenomena to reinsert the experience of light within the public realm.
  4. Faculty Host: Young-Kee Kim
  5. Schedule: arriving on the nihgt of Wed. January 28 and leaving on Friday, January 30
  6. Special event: Panel Discussion
    • Topic: Urban Light
    • Time: 7:00 - 8:30 pm (panel session), 8:30 pm (reception)
    • Location: Logan Performing Art Center Room 501
    • more information
February 5, 2015
  1. Title: The Birth of the Fifth Generation Light Source
  2. Speaker: James Rosenzweig, UCLA
  3. Abstract: The 4th generation light source — the X-ray free electron laser — has revolutionized the way science at the nano-to-mesoscale is done. UCLA researchers have played a key role in this development, and which is moving to a new phase: the birth of what is known as the 5th generation light source – an ultra-compact FEL or similar scheme that is driven by a beam derived from an advanced accelerator, a new class of accelerator based on lasers, plasmas, wakefields and exotic structures. We discuss the characteristics of such a system, beginning with an overview of FEL gain mechanisms, noting that the future will bring low charge beams with extreme high brightness and temporal scales down to the attosecond level. These attributes also are synergistic with the characteristics of advanced accelerators which must operate at quite small accelerating wavelength, demanding small charges and short pulses. In order to fully exploit such beams, a compact FEL system must also reimagine the undulator to utilize very short periods. This in turn fundamentally changes the FEL interaction, bringing it to the threshold of the quantum regime, as well as the Raman regime, in which even for X-ray FELs the longitudinal space charge fields play a dominant role. We highlight in this talk a few of the leading 5th generation light source techniques that are currently under active development.
  4. Faculty Host: Young-Kee Kim
February 12, 2015
  1. Title: High Tc superconductivity in a single atomic layer of FeSe
  2. Speaker: Jenny Hoffman, Harvard
  3. Abstract: The remarkable discovery of superconductivity above 100K in a single atomic layer of FeSe (compared to the relatively mundane Tc=8K in bulk FeSe) prompts tremendous excitement and numerous pressing questions. What is the mechanism of the order-of-magnitude Tc enhancement in FeSe? What is the pairing symmetry? Could FeSe be a topological superconductor? What applications might one envision with such a 2D superconductor? Are there other interface superconductors just waiting to be discovered? I will review current experimental progress towards addressing these questions, then discuss our own growth (via molecular beam epitaxy) and imaging (via scanning tunneling microscopy) of single layer FeSe. We use quasiparticle interference to access the structure of filled and empty states, and to detect the emergence of a new electronic band slightly above the Fermi level. We use the amplitude of the scattering signal to explore the pairing symmetry.
  4. Faculty Host: David Schuster
  5. Postdoc Hosts: TBD
  6. Schedule: arriving on the night of Wed, Feb. 11 and leaving on Thursday evening
February 19, 2015
  1. Title: Topological Metamaterials
  2. Speaker: Vincenzo Vitelli
  3. Abstract:

    One of the open challenges of modern material science is to create artificial structures whose unconventional mechanical response can be programmed by suitable design of their geometry or topology. Such structures termed mechanical metamaterials can be designed to resist catastrophic failure or direct sound propagation.

    In this talk, we discuss metamaterials that exploit topologically protected mechanical states whose spatial extent can be tuned from localized to extended by progressively closing the acoustic gap of the bulk structure. These robust states of motion or stress can be inserted at desired locations by including suitable lattice defects in analogy with their quantum counterparts. The continuum elasticity of the resulting structures can be captured by non-linear field theories with a topological boundary term.

    The topological design rules we uncover will be brought at your fingertips using live demonstrations with macroscopic prototypes based on origami-like and cellular structures. This raises the exiting possibility that, once activated by motors or external fields, similarly designed topological mechanisms could be used as building blocks for molecular robotics or information storage and read-out.

  4. Faculty Host: William Irvine
February 26, 2015
  1. Title: A dynamical way of thinking
  2. Speaker: Amie Wilkinson, University of Chicago
  3. Abstract: The modern mathematical field of Dynamical Systems encompasses a wide range of subdisciplines and techniques. As its scope spreads into more and more areas of mathematics, one is led to redefine Dynamical Systems as a mode of thought, an approach to problem solving. I'll illustrate how a dynamical way of thinking can be applied in a variety of contexts, and how it informs our current perspective.
  4. Faculty Host: Young-Kee Kim
March 5, 2015
  1. Title: Opening a New Chapter in Neutrino Physics
  2. Speaker: Sam Zeller, Fermilab
  3. Abstract: Neutrinos are among the most abundant particles in the universe and they influence an enormous range of physics. Neutrinos allow us to measure the composition of the earth’s crust, they tell us how the sun works, and they allow us to peer into the inner workings of a supernova explosion. Despite all that we have learned via these special particles, there remains a great deal we do not know about neutrinos themselves. The discovery of neutrino masses and mixing a decade ago has raised a number of still unanswered questions. After briefly reviewing what we do know, this talk will highlight several open questions in neutrino physics, explain why these questions are interesting, and discuss the ways future experiments could answer them. The coming years promise new directions and scientific excitement as we better understand these unique subatomic particles and their connections to the world in which we live.
  4. Faculty Host: David Schmitz
  5. Postdoc Hosts: TBD
March 12, 2015
  1. Title: TBD (soft condensed matter theory)
  2. Speaker: Andrea Liu, U.Penn
  3. Abstract: TBD
  4. Faculty Host: Sidney Nagel
  5. Postdoc Hosts: TBD