Topological Spintronics: from the Haldane Phase to Spin Devices
31 Jan 2017 | Online Presentations | Contributor(s): Nitin Samarth
e provide a perspective on the recent emergence of “topological spintronics,” which relies on the existence of helical Dirac electrons in condensed matter. Spin‐ and angle‐resolved photoemission spectroscopy shows how the spin texture of these electronic states can be engineered...
Photonic Structures with Topological Robustness: from Classical to Quantum
09 Jan 2017 | Online Presentations | Contributor(s): Mohammad Hafezi
In this talk, I demonstrate how similar physics can be observed for photons; specifically, how various quantum Hall Hamiltonians can be simulated in an optical platform. I report on the first observation of topological photonic edge state using silicon-on-insulator technology and our recent...
Optical Hyperspace: Light in Metamaterials with Hyperbolic Dispersion
03 Nov 2016 | Online Presentations | Contributor(s): Evgenii Narimanov
The composites with opposite signs of the dielectric permittivity in two orthogonal directions, known as the hyperbolic metamaterials, represent a new "universality class" of optical media, with the light behavior which is qualitatively different from that in either metals or...
The Epithelial-Mesenchymal Transition Its role in metastasis? Can Theory Help Cancer Biology?
19 Oct 2016 | Online Presentations | Contributor(s): Herbert Levine
In order to spread from the primary tumor to distant sites, cancer cells must undergo a coordinated change in their phenotypic properties referred to as the "epithelial-to-mesenchymal" transition. We have studied the nonlinear genetic circuits that are responsible for this...
Quantum Measurement Backaction: From Atoms to Optomechanics
13 Oct 2016 | Online Presentations | Contributor(s): Mukund Vengalattore
The act of measurement has profound consequences on a quantum system. As such, the evolution of a quantum system can be influenced and even controlled through the continuous measurement of its properties. I will describe our studies on such measurement-induced dynamics in systems ranging from...
Tailoring Biomass to Fit the Biofuels Pipeline
10 Oct 2016 | Online Presentations | Contributor(s): Maureen McCann, Nicholas C. Carpita
Second-generation biofuels will be derived from lignocellulosic biomass using biological catalysts to convert the carbon in plant cell wall polysaccharides to ethanol or other biofuels. The Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio) is a DOE-funded Energy Frontier...
Prospects for Using Magnetic Insulators in Spintronics
29 Sep 2016 | Online Presentations | Contributor(s): Mingzhong Wu
This presentation consists of two parts, which together will provide some perspective on the future of using magnetic insulators in spintronics. The first part will touch on the feasibility of using magnetic insulators, in particular, Y3Fe5O12 and BaFe12O19, to produce pure spin currents...
Complex Oxides and the Philosopher’s Stone
26 May 2016 | Online Presentations | Contributor(s): Shiram Ramanathan
In this talk I will discuss the topic of insulator-metal transitions in strongly correlated oxides, their control via disorder, orbital occupancy and electric fields and challenges these systems pose to our contemporary understanding of emergent phenomena in ionic lattices.
Piezotronics in 2D Piezoelectric Semiconductors
01 Apr 2016 | Online Presentations | Contributor(s): Wenzhuo Wu
Monolayer MoS2 and other TMDCs have been theoretically predicted to exhibit piezoelectricity due to the strain induced lattice distortion and associated ion charge polarization, suggesting possible applications of these 2D nanomaterials in nano-scale electromechanical devices that take advantage...
Ultrafast Optical Measurements of Spin Polarization in Semiconductors
29 Mar 2016 | Online Presentations | Contributor(s): Vanessa Sih
n this talk, I will describe optical techniques that can measure the magnitude and direction of spin-orbit fields and electrically-generated spin polarization in non-magnetic semiconductors and the modification of the electron spin precession frequency in a bulk semiconductor using an applied...
Tracking Energy Flow From the Nano to Mesoscale with Ultrafast Nanoscopy
22 Mar 2016 | Online Presentations | Contributor(s): Libai Huang
In this talk, I will discuss our recent efforts on elucidating multi-scale energy transfer, migration, and dissipation processes with simultaneous femtosecond temporal resolution and nanometer spatial resolution. We have combined/correlated ultrafast spectroscopy with high spatial resolution...
Oxide Systems – An Answer to the Qubit Problem?
08 Mar 2016 | Online Presentations | Contributor(s): Sudhakar Yarlagadda
One can produce new oxide-based devices by exploiting their tunability, rich physics, and coupling between the various degrees of freedom (such as charge, lattice, spin, etc.). We propose that oxide-based double quantum dots with only one electron (tunneling between the dots) can be regarded as...
Finding Fake Videos With Physics
18 Feb 2016 | Online Presentations | Contributor(s): Rhett Allain
In case you haven’t noticed, the internet is full of videos. Some of these videos are about cats and some about interesting physics topics. You might be surprised to find that some of these online videos are fake (but hopefully you aren’t surprised). But how can you tell if a video...
Single Molecule Imaging in Live Cells
28 Aug 2015 | Online Presentations | Contributor(s): Kenneth Ritchie
Bacteria, such as Escherichia coli and Caulobacter crescentus, are the most studied and perhaps best-understood organisms in biology. The advances in understanding of living systems gained from these organisms are immense....
Women and Physics
13 May 2015 | Online Presentations | Contributor(s): Laura McCullough
A discussion of some of the issues surrounding women's participation in physics. What comes with being of the feminine persuasion in a physics world? What hinders women's participation in physics? What helps? Why is it important? The fun and occasional fury of...
Teaching Science with Science Fiction
13 May 2015 | Online Presentations | Contributor(s): Kelly McCullough, Laura McCullough
Science fiction is one possible tool for increasing engagement in science classrooms, as well as offering opportunities for modeling scientific thinking, illustrating points of scientific interest, and addressing reading and writing standards for classroom content. Join Laura and Kelly...
Progress in Superconducting Qubits
04 May 2015 | Online Presentations | Contributor(s): Robert F. McDermott
I will review progress in the field, with a focus on recent work in Wisconsin in the areas of decoherence and quantum measurement. I will discuss efforts to identify and suppress the dominant source of qubit dephasing, and I will describe a new approach to scalable, high-fidelity qubit...
Teaching Writing in Introductory Physics: the Good, the Bad, and the Revision
21 Apr 2015 | Online Presentations | Contributor(s): Scott Bonham
Written communication is an important skill in almost every field, including science and engineering. Over the last five years I have been evaluating different approaches for teaching and supporting development of technical writing skills. A common approach is providing students with written...
Integrated Imaging: Creating Images from the Tight Integration of Algorithms, Computation, and Sensors
21 Apr 2015 | Online Presentations | Contributor(s): Charles Addison Bouman
This talk presents some examples of state-of-the-art integrated imaging systems based on computed tomography (CT), transmission electron microscopy (STEM), synchrotron beam imaging, optical sensing, and scanning electron microscopy (SEM). For each of these examples, we also explore their use and...
Optically Probing the Nanoarchitecture of Cells and Tissues
19 Mar 2015 | Online Presentations | Contributor(s): Steven L. Jacques
This seminar presents our current work on using light to probe the nanoarchitecture (1-1000 nm) of cells and tissues. In particular, our experiments with SHG and holographic imaging of angular scattering of photons explore the structure of collagen fibers. Our work with confocal reflectance...
Of Soot and Sunflowers
16 Dec 2014 | Online Presentations | Contributor(s): Christopher M. Sorensen
In this talk I will describe some of my researches into soot and other aggregate structures; an unlikely journey of discovery to find fractal structures with non-Euclidian dimensionality, gel networks of graphene that tenuously span space and common Fibonacci themes between spirals, sunflowers...
Incorporation of Studio Exercises for Physics Instruction at all Levels
11 Dec 2014 | Online Presentations | Contributor(s): Christopher M. Sorensen
In this talk I will give examples of studio activities from all three and observations with regard to how well this form of instruction works. I will also discuss problems incurred with regard to class size and time limitations. My goal is to encourage my audience to implement studio instruction...
Strain Engineering of 2D Crystals
08 Oct 2014 | Online Presentations | Contributor(s): Bennett Goldberg
Two-dimensional materials are flexible, transparent, compatible with living systems, and can enable new devices and physics based on their unique properties. One unique property is the ability of 2D crystals a single atom thick to undergo massive amounts of strain without failure. Since strain...
Sequencing a Genome by a Torrent of Ions: How an Old pH-Meter Got Its Groove Back
11 Apr 2014 | Online Presentations | Contributor(s): Muhammad A. Alam
The ability to read the book of life, written in the genome of an organism, has been one of the most exciting development of our time. The first version of human genome was announced circa 2000 and it took a decade of industrial-scale collaboration and billions of dollars of funding. Today, we...
Quantum Band Engineering in III-nitride Semiconductors
12 Oct 2013 | Online Presentations | Contributor(s): Oana Malis
In this talk I will focus on our efforts to creatively exploit the unique properties of nano-structured III-nitride materials for novel light emitters and detectors in the currently under-developed near- and far-infrared ranges. Due to large electron effective mass, the nitride intersubband...
Nanoscale Electrothermal Energy Transport
12 Jul 2013 | Online Presentations | Contributor(s): Ali Shakouri
Thermoreflectance imaging is used to study Peltier cooling and Joule heating in devices with 800ps time and submicron spatial resolution. The ballistic heat conduction and the transition between energy and entropy transport in ultra short times and in thin film devices will be discussed. Finally...
Physics of the Piano
12 Jul 2013 | Online Presentations | Contributor(s): Nicholas J. Giordano
Why does a piano sound like a piano? A similar question can be asked of virtually all musical instruments. A particular note, such as middle C, can be produced by a piano, a violin, and a clarinet. Yet, it is easy for even a musically untrained listener to distinguish between these instruments....
Catching Sunlight: Lessons from Photosynthesis
10 Jul 2013 | Online Presentations | Contributor(s): Sergei Savikhin
We will discuss the physics of early processes in photosynthesis revealed by ultrafast laser spectroscopy.
The Secret Life of Electrons in High Temperature Superconductors
19 Jun 2013 | Online Presentations | Contributor(s): Erica W. Carlson
Nanoscale Spectroscopy and Plasmonics in Infrared
19 Apr 2012 | Online Presentations | Contributor(s): Mikhail Belkin
In this talk, I will present the results of two of our research projects. I will start with a simple technique for nanoscale mid-infrared spectroscopy that we have developed recently. Subwavelength resolution is achieved by detecting optical absorption through measuring local photothermal...
Putting the Electron’s Spin to Work
14 Apr 2011 | Online Presentations | Contributor(s): Daniel Ralph
I will discuss recent progress in experimental techniques to control the orientations of nanoscale magnetic moments and electron spins, and to use these new means of control for applications. One powerful new capability arises from the fact that thin magnetic layers can act as filters for spins.
A Half Century of Nonlinear Optics
22 Mar 2011 | Online Presentations | Contributor(s): Robert W. Boyd
In this talk, we first present a review of the development of the field of nonlinear optics, and we then survey some areas of recent research including quantum imaging and implications of the ability to control the group velocity of light.