Colloquia & Seminars
  • Informal Statistical Physics Seminar
    Speaker Name: Professor Stephen Brush

    Speaker Institution : UMCP

    Title: Physics a Century Ago: Memorable or Forgotten?

    Notes: As in the past, each seminar will be preceded by an INFORMAL CAFETERIA LUNCH to which all are welcome, departing from Room 1108 about five minutes after 12:00 (Noon).

    For further information contact:
    Professor Christopher Jarzynski, This e-mail address is being protected from spambots. You need JavaScript enabled to view it , (301)405-4878 Professor John D. Weeks, This e-mail address is being protected from spambots. You need JavaScript enabled to view it , (301)405-4802 Professor Michelle Girvan, This e-mail address is being protected from spambots. You need JavaScript enabled to view it , (301)405-1610.
    When: Tue, September 23, 2014 - 1:15pm
    Where: Room 1116, IPST Building, Bldg 85
  • Physics Colloquium
    Speaker Name: Brian DeMarco

    Speaker Institution: University of Illinois at Urbana

    Title: Ultracold Disordered Quantum Gases

    Abstract: Disorder is the rule, rather than the exception, in nature. Despite this, we understand little about how disorder affects interacting quantum matter. I will give an overview of our experiments using ultracold atom gases to probe paradigms of interacting disordered quantum particles. We introduce disorder to naturally clean atomic gases cooled to billionths of a degree above absolute zero using focused optical speckle. I will explain how we observe Anderson localization---a spectacular phenomenon in which interference prevents waves from propagating in a disordered medium---of quantum matter in three dimensions. I will also show how we combine speckle with an optical crystal to emulate a completely tunable and precisely characterized disordered quantum solid. In these optical lattice experiments, we realize disordered Hubbard models that we use to answer critical questions regarding how disorder impacts the properties of electronic solids, such as superconductors and metals.
    When: Tue, September 23, 2014 - 4:00pm
    Where: PSC Lobby
  • LPS Seminar
    Speaker Name: Dr. Alison Flatau and Dr. Bethanie J. Stadler

    Speaker Institution : UMCP and UMN

    Title: Magnetostrictive multilayered Fe-Ga/Cu nanowires

    Abstract : Iron-gallium alloys known as Galfenol, Fe100−xGax, 10 ≤ x ≤ 25 at.% have been investigated due to their unique combination of magnetostrictive properties (elongations of ~300-400 ppm) and mechanical properties (high elastic modulus and tensile strength). They are known as the first of the class of structural magnetostrictive alloys and are being considered for use in next generation sensors, actuators, energy harvesting devices and even biological applications. In this presentation, we focus on magnetostriction in nanowires (NW) of these alloys fabricated using electrodeposition methods. We fabricate the nanowires as multilayered structures with alternating Fe-Ga and Cu segments to minimize the relative magnitude of the contribution of shape anisotropy to magnetic domain alignment. Results showing magnetic properties will be presented and nanowires attributes characterized (magnetization process, magnetization rotation and hysteresis). The presentation will include results from a recently developed characterization method showing measurement of the dimensions of an individual NW as it changes with induced magnetization as well as utilizing an NW array as a pressure sensing element. On-going investigations into a concept for using the nanowires fabricated using these methods to develop magnetic sensor arrays for one-pass two-dimensional magnetic recording media will also be introduced.
    When: Wed, September 24, 2014 - 3:30pm
    Where: Lab for Physical Sceinces
  • Plasma Physics Seminar
    Speaker Name: George Wilkie

    Speaker Institution : University of Maryland

    Title: Non-Maxwellian Alpha Particles in Gyrokinetics

    Abstract : Gyrokinetic simulations have traditionally been performed assuming a Maxwellian equilibrium distribution. However, there are many situations in which one is interested in modelling a weakly-collisional species, such as fusion-produced alpha particles in tokamaks. This talk will provide an overview of non-Maxwellian gyrokinetics, explore situations in which the non-Maxwellian nature of a species is important, and present recent results on the transport of slowing-down alpha particles.
    When: Wed, September 24, 2014 - 4:00pm
    Where: ERF 1207
  • Applied Dynamics Seminar
    Speaker Name: Jacob Bedrossian

    Speaker Institution : UMD Department of Mathematics

    Title : Patlak-Keller-Segel and related models for collective motion of organisms
    When: Thu, September 25, 2014 - 12:30pm
    Where: IREAP Large Conference Room, ERF 1207
  • Refreshments for the CNAM Condensed Matter Colloquium

    When: Thu, September 25, 2014 - 1:30pm
    Where: phys room 1305F, the "new" Toll Room
  • CNAM Condensed Matter Colloquium
    Speaker Name: Javad Shabani

    Speaker Institution: UCSB

    Title: Fabrication and characterization of gate-defined structures in epitaxially grown InAs heterostructures

    Abstract: Theory and recent experiments suggest that nanowires of narrow band gap semiconductors, such as InAs, are a suitable platform for realization of topological states of matter. Molecular beam epitaxy (MBE) growth of large area InAs two-dimensional systems (2DESs) combined with semiconductor processing techniques (top-down approach) provides an avenue toward substantially more complex architectures than can be achieved using vapor-liquid-solid self-assembled nanowires. Fabrication of gate-defined devices on these heterostructures is highly desirable as it offers the possibility of tuning confinement potential, carrier density and spin orbit coupling while maintaining the mobility of the parent 2DES. However, reliable gating has proven difficult in InAs due to gate leakage and hysteretic behavior. In this talk, we show that these difficulties could be surmounted using epitaxial growth of strained InAs quantum wells in metamorphic heterostructures. At liquid helium temperature electron mobilities in excess of 600,000 cm^2/Vs are now achieved. The gate-controlled mobility dependence on carrier density indicates mobility is limited due to scattering from background impurities. Consistent with this picture, we find a metal insulator transition at very low critical density. We also demonstrate the first gate-defined one-dimensional channels on high mobility InAs 2DES and discuss their future prospects for fabricating complicated wire networks.

    Host: James Williams
    When: Thu, September 25, 2014 - 2:00pm
    Where: phys room 1201
  • JQI Seminar
    Speaker: Gleb Findelstein

    Speaker Institution: Duke

    Title: "Quantum critical behavior and Majorana fermions in a resonant level coupled to a dissipatie environment"

    Abstract: to follow

    Host: James Williams
    When: Mon, September 29, 2014 - 11:00am
    Where: CSS 2400
  • EPT Seminar
    Speaker: Daniel Stolarski, CERN

    Title: Emerging Jets

    Abstract: I will describe a new collider object we have termed emerging jets.
    These can arise when there is a confining dark sector connected to the
    Standard Model by a TeV scale mediator, a scenario that is well
    motivated by dark matter considerations. The signature of an emerging
    jet is O(10) displaced vertices inside the jet each with different
    impact parameter, and a small number of prompt tracks. I will describe
    strategies that can be used to discover emerging jets even if they
    have very small cross sections.
    When: Mon, September 29, 2014 - 3:00pm
    Where: PSC 3150
  • EPT Joint Seminar w/ Johns Hopkins
    Joint Particle theory-experiment Maryland-Hopkins Seminar

    Seminar will be preceded by lunch at 12:30 pm. The talk is from 2:00 to 3:00 pm.

    Title: Neutrinos: Recent Developments and Open Questions

    Speaker: André de Gouvêa, Northwestern University

    Abstract: Nonzero neutrino masses are the most concrete evidence of physics beyond the standard model to date. I will provide an overview of the current status of neutrino physics, concentrating on recent experimental and theoretical developments. I will also discuss outstanding experimental and theoretical issues, and the program that is required in order to fully explore the neutrino mass puzzle, which ranges from precision neutrino oscillation searches to searches for charged-lepton flavor violation to the pursuit of a finite proton lifetime.
    When: Tue, September 30, 2014 - 12:30pm
    Where: PSC 3150, University of Maryland
  • Informal Statistical Physics Seminar
    Speaker Name: Professor Maria Cameron

    Speaker Institution : UMCP

    Title : Metastability, Spectrum and Eigencurrents of the Lennard-Jones-38 Network
    When: Tue, September 30, 2014 - 1:15pm
    Where: Room 1116 IPST Building, Bldg 85
  • Physics Colloquium
    Speaker Name: Johnpierre Paglione

    Speaker Institution: University of Maryland

    Title: Non-trivial pursuits: finding topological states of matter

    Abstract: Topological insulator (TI) materials, with metallic boundary states protected against time-reversal-invariant perturbations, are a new and exciting avenue for realizing exotic quantum states of matter with strong potential for new and advanced technologies. As usual, predictions of new three-dimensional TI materials are widespread but obtaining conclusive proof of the existence of non-trivial TI states continues to be a challenge. To date, the majority of effort has focused on a family of layered bismuth-based compounds now regarded as the archetype TI material. However, these materials are in reality good conducting metals with bulk carriers, requiring advanced device and measurement techniques to dig out the intrinsic topological state properties. I will discuss our efforts to advance this state of affairs by improving on materials quality and diversity, focusing on both non-interacting Bi2Se3 and the "new" mixed-valence topological Kondo insulator SmB6. Using unique synthesis techniques as well as careful low-temperature experiments, we have new convincing evidence and characterization of the topologically non-trivial surface states in these materials.
    When: Tue, September 30, 2014 - 4:00pm
    Where: PSC Lobby
  • Applied Dynamics Seminar
    Speaker Name: Juan Restrepo

    Speaker Institution : University of Colorado, Department of Applied Mathematics

    Title: Inhibition guarantees ceaseless cortex dynamics
    When: Thu, October 2, 2014 - 12:30pm
    Where: IREAP Large Conference Room, ERF 1207
  • Refreshments for CNAM Condensed Matter Colloquium

    When: Thu, October 2, 2014 - 1:30pm
    Where: physics room 1305F, the "new" Toll Room
  • CNAM Condensed Matter Colloquium
    Speaker: Dr. Vidya Madhaven, Boston College
    Title & Abstract: TBD
    When: Thu, October 2, 2014 - 2:00pm
    Where: physics room 1201
  • JQI Seminar
    Speaker Name: Leon Balents

    Speaker Institution: U. California Santa Barbara

    Title and Abstract to follow

    Host: Jimmy Williams
    When: Mon, October 6, 2014 - 11:00am
    Where: CSS 2400
  • EPT Seminar
    Title: tk

    Speaker: Michael Graesser, Los Alamos National Laboratory

    Abstract: tk
    When: Mon, October 6, 2014 - 3:00pm
    Where: PSC 3150
  • Biophysics Seminar
    Speaker Name: Enrico Gratton

    Speaker Institution : Laboratory for Fluorescence Dynamics, University of California, Irvine

    Title: Laboratory for Fluorescence Dynamics, University of California, Irvine

    Abstract : The coordination of cell functions requires that molecules move in the cell interior to find their partners and eventually to form complexes. In the cell interior, the mechanisms for molecular motion are poorly understood. While in an isotropic fluid diffusion is the default mechanism of motion, in the cell interior diffusion is hindered by barriers and by transient binding. Also molecules can move by active transport. One universal transport processes which is still debated is the shuttling of molecules between the cytoplasm and the nucleus. It is well established that molecules must pass through the nuclear pore complexes to go from the cytoplasm to the nucleus. The structure of the nuclear pore complex has been elucidated. The nuclear pore has the additional capability to selectively allow specific molecules to be transported between the cytoplasm and the nucleus. Despite many years of research, the physical mechanism responsible for the nuclear transport and pore selectivity remains elusive.
    When: Mon, October 6, 2014 - 4:00pm
    Where: 0112 Chemistry Building
  • CMTC Seminar
    Speaker Name: Joaquin E. Drut

    Speaker Institution: University of North Carolina

    Host: Bitan Roy
    When: Tue, October 7, 2014 - 11:00am
    Where: 2205 Toll Physics Building
  • Physics Colloquium-Shih-I Pai Lecture
    Speaker Name: Anneke Levelt Sengers

    Speaker Institution: NIST

    Title: Pride and Prejudice in Science and Engineering

    Abstract: During my career I have worked with scientists, engineers, and postdoctoral collaborators, both men and women, from the US and from many foreign countries. In the past ten years, within the context of the Network of the Academies of Sciences (www.iap.org), I have chaired first a global, then a Western Hemisphere initiative (www.ianas.org) addressing the low representation of women in science and technology. Sociologists have produced solid evidence of gender prejudice even within the physical
    sciences that take pride in their objectivity. The IANAS book: “Women Scientists in the Americas; their Inspiring Stories” strikingly illustrates culture-dependent gender prejudice that keeps the physical sciences and engineering preponderantly male occupations in countries such as the US, UK, and Germany. The near-absence of women from engineering, and ignorance about local culture and gender roles adversely affect development work by foreign male engineers serving the poor in the third world. Indeed, both women engineers and social scientists have unique roles to play in overcoming cultural prejudices which waste women’s talents and hamper development work.
    When: Tue, October 7, 2014 - 4:00pm
    Where: Physics 1412
 

Department of Physics


University of Maryland
College Park, MD 20742-4111
Phone: 301.405.3401
Fax: 301.314.9525