Colloquium 2017
| Date | Speaker | Institution | Title |
| Jan 20 | Karl Gebhardt | University of Texas at Austin | From black holes to dark energy, using the eyes of Texas |
| Feb 3 | Martin Mittendorff | University of Maryland, College Park | Graphene and THz radiation: time resolved spectroscopy and applications |
| Feb 17 | Junichiro Kono | Rice University | Dicke phenomena in condensed matter |
| Mar 3 | Ohad Shemmer | University of North Texas | Multiwavelength diagnostics of quasar accretion power |
| Mar 10 | Tsampikos Kottos | Wesleyan University | Non-Hermitian wave transport: new possibilities and challenges |
| Apr 7 | Bibhudutta Rout | University of North Texas | Materials analysis and modifications at micro-nanoscale using ion beams |
| Apr 24 | JaeHoon Jung | Texas A&M University | Electron Tomography: integrating nanoscale subcellular structures and their functions |
| Apr 28 | Ryan Suess | U.S. Naval Research Laboratory | Tuning the functionality of materials with reversible phase transitions |
| May 1 | HyeongJun Kim | Harvard Medical School | The power of single: Revealing mechanisms of molecular machines in single-molecule imaging |
| Sep 15 | Warren Skidmore | Thirty Meter Telescope | The thirty meter telescope observatory: the next generation ground based optical/infra-red observatory |
| Sep 22 | Marek Szczepanczyk | Embry-Riddle Aeronautical Univ. | Core-collapse supernova science with advanced detectors and beyond |
| Sep 29 | Fredrick Jenet | UTRGV | NewSpace: The dawn of the next space age |
| Oct 13 | Andreas Hanke | UTRGV | Kinetic Pathways of topology simplification by type-II topoisomerases in knotted, supercoiled DNA |
| Oct 20 | Philip Kim | Harvard University | Materials in 2-dimension and beyond: platform for novel electronics and optoelectronics |
| Oct 27 | Manoj Peiris | UTRGV | Towards Violation of Classical Inequalities using Quantum Dot Resonance Fluorescence |
| Nov 3 | Michele Zanolin | Embry-Riddle Aeronautical Univ. | Multimessenger astronomy for Core Collapse Supernovae |
| Nov 10 | Hasina Huq | UTRGV | Growth and Characterization of Gallium Based Thin Films for Bio Sensors Applications |
| Nov 17 | Guru Naik | Rice University | Hot nanophotonics: From hot carriers to hot thermal emitters |
| Dec 1 | Jaehong Park | Lawrence Berkeley National Laboratory | Plasma Physics using Particle-in-Cell Simulations: Applications to Space and Laboratory |
Friday, March 10, 2017
Time: 10:50am - 12:20pm
Location: BLHSB 1.104 (Brownsville), EACSB 1.104 (Edinburg)
Non-Hermitian Wave Transport: New possibilities and challenges
While there is absolutely no doubt as to the usefulness of gain mechanisms in order to boost signals and transfer information, loss on the other hand, is typically considered an “anathema” – a feature to be avoided if at all possible - since it degrades the efficiency of the structures employed to perform useful operations on these signals. Currently however, an alternate viewpoint is emerging aiming to manipulate absorption in classical wave systems, and via a judicious design of the medium impedance profile, to achieve new classes of synthetic structures with altogether new physical behavior and novel functionality. We shall present some example cases where manipulation of loss can find practical applications and we shall provide our vision of the future of Non-Hermitian wave transport.
Speaker: Dr. Tsampikos Kottos (Wesleyan University)
About the speaker: Dr. Tsampikos Kottos received his PhD in theoretical solid-state physics from the University of Crete in 1997. At the same year, he received the Feinberg Fellowship and joined the Quantum Chaos group of U. Smilansky at the Weizmann Institute of Science, Israel. During this period he introduced and developed one of the standard models of wave chaos, "the quantum graphs". In 1999 he moved to Germany, originally as a postdoctoral research fellow and latter as a senior researcher, in the group of T. Geisel at the MPI for Dynamics and Self-Organization in Gottingen. In 2005 he became an Assistant Professor at Wesleyan University, USA were he has continued working on theoretical aspects of wave transport with main emphasis on non-Hermitian electromagnetism. In 2011 he was awarded tenure and in 2013 he became the Douglas J. and Midge Bowen Bennet Chair. In 2015 he was elected full professor of physics and in 2016 professor of Mathematics (courtesy appointment). Dr. Kottos received in 1997 a US European Office of Air Force Research and Development Fellowship while in 2006 he was awarded the International Stefanos Pnevmatikos Award given biannually to outstanding young researchers in the field of nonlinear phenomena. He is the author or co-author of more than 130 peered published review papers while he has received a number of grants from funding agencies like ONR, NSF, AFOSR and BSF.
Friday, April 7, 2017
Time: 10:50am - 12:20pm
Location: BLHSB 1.104 (Brownsville), EACSB 1.104 (Edinburg)
Materials analysis and modifications at micro-nanoscale using ion beams
Ion beams with energies from a few keV to MeV have been used for materials analysis, synthesis and modifications in a wide range of fields involving metallurgy, semiconductors, to biomaterials. Recent advances in the manufacturing process, ion optics theory and computer control systems have led to the development of high spatial resolution (sub-micro meter) High Energy Focused Ion Beam Systems mainly using H+ or He+ ions. These ion beams allow quantitative elemental analysis of a wide range of elements with unprecedented detection sensitivity in a short time, especially for physiologically important metals (ppm level). Microscopic multi-element images of a sample are simultaneously provided. Heavy ions of broader diameter have been used for synthesis of micro-nanostructures at near surfaces to layers buried deep below the substrate surfaces, with applications in many different areas, spanning from the microelectronic industrial production to the synthesis of new materials system (e.g. thin layers ~30 μm of Si for solar cell applications). In this presentation, we will be illustrating examples of quantitative multi-dimensional trace elemental analysis in many systems from semiconductors to biological materials at cellular levels. Also examples of multi-dimensional metal-semiconductor nano-structures synthesized in semiconductors will be presented.
Speaker: Dr. Bibhudutta Rout (University of North Texas)
About the speaker: Dr. Bibhudutta Rout received his Ph.D. in experimental condensed matter physics from the Institute of Physics (Utkal University), India in 2001. His Ph.D. work involved growth and characterization of epitaxial metallic layers on semiconductors and their self-assembled micro-structures. He developed India’s first ion microbeam and surface physics beamlines associated with an ion accelerator. In 2001, he accepted an Australian Research Council sponsored postdoctoral research fellowship at the University of Melbourne, where he took the leadership in development and application of new-generation high energy focused ion beam (HEFIB) or more popularly known as “nuclear microprobe” systems. In 2003, he moved to University of Louisiana at Lafayette as a research associate to work on HEFIBs using magnetic and electrostatic lenses. In 2007, he joined the University of North Texas as an Assistant Professor and in 2013, he was awarded tenure and promoted to Associate Professor. He along with three other faculty members shares the accelerator facilities at the Ion Beam Modification and Analysis Laboratory (IBMAL) in the physics department at UNT. His current research involves synthesis, modification and analysis of materials for electronic, energy and biomedical applications. He is the author of more than 100 peered review publications. His research has been funded by NSF, DOD, ORAU, and Lockheed Martin including one NSF major research instrumentation project for development of new generation HEFIB.
Monday, April 24, 2017 (Brownsville Campus)
Time: 11:00am - 12:00pm
Location: Cavalry Conference Room
*Lunch/Meet with students 12:00pm - 1:00pm
Tuesday, April 25, 2017 (Edinburg Campus)
Time: 3:10pm - 4:10pm
Location: EPHYS 1.119
*Meet with students 4:10pm - 4:40pm
Electron Tomography: Integrating nanoscale subcellular structures and their functions
Electron tomography has been increasingly used to provide 3-dimensional information of subcellular organelles and macromolecular complexes with an exceptional resolution. Such electron tomography studies on synapses have provided valuable findings and novel insight for a comprehensive understanding of how the nervous system functions. In this talk, I present my electron tomography study on synaptic vesicle priming, a crucial regulatory step to mediate synaptic transmission. My work first quantified the spatial relationship of synaptic vesicles with the presynaptic membrane and the active zone material commonly observed at the active zone with a few nanometer spatial resolution, revealing strong evidence that the contact area of the synaptic vesicle with the presynaptic membrane is a structural correlate of synaptic vesicle priming and that the area is regulated by the active zone material. These findings will be of interest to anyone studying aspects of synaptic physiology that govern how the nervous system performs its various specialized tasks in normal and disease states. Such quantitative electron tomography approaches will also be useful to obtain nanometer-scale 3-dimensional information of other biological and non-biological materials because of its general applicability.
Speaker: Dr. JaeHoon Jung (Texas A&M University, Department of Biology)
About the speaker: Dr. Jung received his Ph.D. in Physics in 2009 from Stanford University, California, under the supervision of Uel J. McMahan (Department of Neurobiology/Structural Biology) and Sebastian Doniach (Department of Physics/Applied Physics). After graduating Dr. Jung joined the Department of Biology at Texas A&M University as Postdoctoral Research Associate with Uel J. McMahan. Since 2012 Dr. Jung has worked as Research Assistant Professor at the Department of Biology, Texas A&M University.
Friday, April 28, 2017
Time: 10:50am - 12:20pm
Location: BMAIN 1.224 (Brownsville), EACSB 1.104 (Edinburg)
Tuning the Functionality of Materials with Reversible Phase Transitions
There has been considerable interest in vanadium dioxide (VO2) due to its sharp, insulator to metal transition (IMT) that produces highly variable optical and electrical properties. The IMT is coupled to a monoclinic to tetragonal structural change at 68 oC, that can be induced via the application of external stimuli such as thermal, chemical, stress/strain, and electrical excitations. The changeable nature of the material response makes VO2 an attractive candidate for numerous applications such as terahertz emitters, smart window coatings, and ultrafast switches. In this talk we will discuss the properties of epitaxial VO2 films grown by laser pulse deposition (PLD) and report the effect of PLD growth conditions on the stress/strain state of the VO2 layer. Strain engineering results in dramatic changes to the electrical and optical properties of the film, revealing both interesting IMT physics as well as a means for tailoring the response of VO2-based devices. In the second part of the talk, active terahertz devices fabricated from VO2 films will be discussed.
About the speaker: Ryan J. Suess received his Bachelor and Master of Science degrees both in Electrical Engineering from the University of Wisconsin - Madison in 2002 and 2004. In 2005 he joined the Massachusetts Institute of Technology Lincoln Laboratory as a member of the associate technical staff where he worked on problems related to remote sensing, lidar, and sensor systems development. His doctoral work was done at the University of Maryland under Professor Thomas Murphy where he investigated nonlinear and ultrafast optics of 2D materials and was the recipient of the Future Faculty Fellowship Award. In 2016 he joined the U.S. Naval Research Laboratory as a contracting research scientist where he continues to study ultrafast material physics.
Monday, May 1, 2017 (Brownsville Campus)
Time: 11:00am - 12:00pm
Location: Cavalry Conference Room
*Lunch/Meet with students (Q&A): 12:00pm - 1:00pm at Cavalry Conference Room
Tuesday, May 2, 2017 (Edinburg Campus)
Time: 3:00pm - 4:00pm
Location: EPHYS 1.119
*Meet with students (Q&A): 4:00pm - 4:30pm at EPHYS 1.119
The Power of single: Revealing mechanisms of molecular machines in single-molecule imaging
The advent of single-molecule techniques has enabled biophysicists to obtain in-depth information by looking into “individual” biological molecules. By discussing single-molecule biophysics studies on two protein machines (Myosin VI cellular motor protein and SMC) as examples, we show that single-molecule techniques based on physics principles provide a powerful toolset in answering important biological questions. For example, SMC (Structural Maintenance of Chromosomes) is a huge protein machine playing essential roles in chromosome condensation and DNA repair. Despite intensive efforts, it has remained unclear how SMCs structure DNA and how their mechanochemical cycle regulates their interactions with DNA. We combined force-based multiplexed single-molecule tools (e.g. flow-stretching assay) with fluorescence-based imaging, and visualized how a single Bacillus subtilis bacterial SMC (BsSMC) interacts with flow-stretched DNAs. We find that a single BsSMC can vary its initial interaction with DNA – switching between being static and mobile. On the other hand, multiple BsSMCs form distinct clusters that are capable of compacting DNA by both bending and bridging two different segments of DNA. During these steps, adding ATP (cellular energy source) leads to faster compaction, but is not required. These mechanistic details would not have been revealed without investigating individual molecules.
Speaker: Dr. HyeongJun Kim (Harvard Medical School, Department of Biological Chemistry and Molecular Pharmacology)
About the speaker: Dr. Kim received his Ph.D. in Physics in 2011 from the University of Illinois at Urbana-Champaign under the supervision of Paul R. Selvin. Since 2011 Dr. Kim has worked as Postdoctoral Research Associate with Joseph Loparo at the Department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School, Boston.
Friday, September 15, 2017
Time: 12pm - 1pm
Location: BBRHB 1.222 (Brownsville), EACSB 1.106 (Edinburg)
The Thirty Meter Telescope Observatory: The Next Generation Ground Based Optical/Infra-Red Observatory
After a construction status update, I will describe how the telescope design has been developed to support a broad range of observing capabilities and how the observatory is being engineered. I'll discuss some of the observational capabilities that the Thirty Meter Telescope will provide and some of the areas of study that will benefit from the TMT's capabilities, specifically synergistic areas with new and future proposed astronomical facilities. Finally, I will describe the avenues through which astronomers can provide input or become involved in the planning of the project, the potential NSF partnership, prioritizing the development of 2nd generation instruments and directing the scientific aims for the observatory.
Speaker: Dr. Warren Skidmore (Thirty Meter Telescope)
About the speaker: Dr. Warren Skidmore has been employed within the TMT project for 15 years. After previously carrying out research into interacting binary or Cataclysmic Variable stars he joined TMT to participate in the exploration of candidate sites for the observatory, was involved in the development of some of the telescope optics control systems, evaluation of the operation of existing observatories and validation of the design tools being used to design the TMT. He facilitates the communications between the science community and the TMT project and is deeply involved in the collection of the science drivers for the observatory and the derivation of the technical design requirements for the observatory from the many potential science programs.
Friday, September 22, 2017
Time: 12pm - 1pm
Location: BBRHB 1.222 (Brownsville), EACSB 1.106 (Edinburg)
Core-Collapse Supernova Science with advanced detectors and beyond
Core-Collapse Supernovae are the spectacular and violent deaths of massive stars. The detection of Gravitational Waves from the initial moment of a collapsing star could deliver the next revolution in understanding space-time and matter in extreme conditions. In my presentation, I will give an overview of searches targeting supernova signals in initial LIGO and Virgo data. I will discuss some of the current efforts to detect Gravitational Waves with advanced detectors, reconstruct the waveforms and extract physical information, like the dynamics of revived shock. Additionally, I will give a brief overview of the studies about extracting physics from collapsing stars with the third-generation interferometers.
Speaker: Marek Szczepanczyk (Embry-Riddle Aeronautical University)
About the speaker: Marek Szczepanczyk is currently a PhD student at Embry-Riddle Aeronautical University in Prescott, Arizona. Marek got his Bachelor and Master degrees from University of Warsaw in Theoretical Physics. For the last 1.5 years he is the liaison of the LIGO/Virgo Supernova Working Group, leading a group of around ~25 people. He is also leading the search for GW from Core-Collapse Supernovae in O1-O2 advance detector data.
Friday, September 29, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
NewSpace: The dawn of the next space age
Space is no longer in the hands of big government. Over the last decade, there has been a concerted effort to foster the privatization of space exploration. This is being driven by many sides, from governmental policies to budding entrepreneurs. This presentation will introduce the concept of NewSpace, the new space age, discuss recent events that are shaping the industry, and how UTRGV’s Center for Advanced Radio Astronomy, home of the STARGATE program, is creating opportunities for UTRGV faculty, staff, and students to play a role the NewSpace age as a leading center of near and deep space exploration.
Speaker: Dr. Fredrick Jenet (The University of Texas Rio Grande Valley)
About the speaker: Dr. Jenet arrived in Brownsville 12 years ago with a dream of using space exploration to change the lives of people in the region and make South Texas known globally as a leader in mankind’s effort to explore the universe. Before coming here, he did his undergraduate work at the Massachusetts Institution of Technology and his graduate work at the California Institute of Technology, both in Physics. After a brief foray into the oil industry, where he obtained two patents for oil field technologies, he worked at NASA’s Jet Propulsion Laboratory where he did seminal work in the field of pulsar timing and gravitational wave detection, which lead to the creation of an international collaboration that is building a galactic scale observatory for gravitational waves. Once in South Texas, Dr. Jenet went on to create several integrated research and education programs that get our students involved in scientific research early in there careers. These programs, known as the Arecibo Remote Command Center and the Low Frequency All Sky Monitor, enabled him to create the Center for Advanced Radio Astronomy, a center responsible for obtaining over 50 million dollars in research funding for itself and its partners. Most recently, Dr. Jenet created a model strategic alliance with SpaceX known as STARGATE.
Friday, October 13, 2017
Time: 12pm - 1pm
Location: BBRHB 1.222 (Brownsville), EACSB 1.106 (Edinburg)
Kinetic Pathways of topology simplification by type-II topoisomerases in knotted, supercoiled DNA
The topological state of covalently closed, double-stranded DNA is defined by the knot type, K, and the linking number difference from relaxed DNA, ΔLk. DNA topoisomerases are essential enzymes that regulate topological states of DNA in vivo: type-I topoisomerases (topo-Is) change ΔLk, thereby regulating the torsional tension, whereas type-II topoisomerases (topo-IIs) change both (ΔLk, K) by passing one DNA helix through another. A critical biological function of type-II enzymes is the elimination of knots in DNA because their presence impedes transcription and replication. It has been a long-standing puzzle how small type-II enzymes select passages that unknot large DNA molecules, since topology is a global property which cannot be determined by local DNA-enzyme interactions. Previous studies addressing this question have focused on the equilibrium distribution P(ΔLk, K). Motivated by the fact that topo-IIs reduce the knotting level below equilibrium at the expense of ATP hydrolysis, we set out to study topoisomerase activity in the framework of non-equilibrium thermodynamics. We consider the dynamics of transitions in a network of topological states (ΔLk, K) induced by type-II and type-I action by solving the master equation for the time-dependent probability distribution P(ΔLk, K; t). We fully characterize non-equilibrium steady states generated by injecting DNA molecules in a given topological state in terms of stationary probability distributions and currents in the network. This allows us, for the first time, to predict detailed kinetic pathways of topoisomerase action as a function of geometry of the enzyme. In particular, we find that unknotting activity of topo-II is significantly enhanced in DNA molecules which maintain a supercoiled state with constant torsional tension; this is relevant for bacterial cells in which the torsional tension is maintained by a homeostatic mechanism using topo I and DNA gyrase.
Speaker: Dr. Andreas Hanke (The University of Texas Rio Grande Valley)
About the speaker: Dr. Hanke wrote his diploma thesis with Prof. W. Zwerger at the Physics Department of the Ludwig Maximilian University Munich, Germany, on a topic of mesoscopic quantum systems. In his Ph.D. thesis with Prof. S. Dietrich at the University of Wuppertal, Germany, he studied entropic forces in polymer solutions and between colloidal particles. After his PhD he did a 2-year postdoc at MIT, a Marie Curie Fellowship at Oxford University (UK), and a postdoc at the University of Stuttgart (Germany), before coming to Brownsville in 2004. He has worked in the fields of mesoscopic quantum systems, Casimir effect, soft condensed matter physics, and biological physics. His vision is to build a research group that investigates complex biological systems and mesoscopic systems from an ab initio standpoint.
Friday, October 20, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
Materials in 2-dimension and beyond: platform for novel electronics and optoelectronics
Heterogeneous interfaces between two dissimilar materials are an essential building block for modern semiconductor devices. The 2-dimensional (2D) van der Waals (vdW) materials and their heterostructures provide a new opportunity to realize atomically sharp interfaces in the ultimate quantum limit for the electronic and optoelectronic processes. By assembling atomic layers of vdW materials, such as hexa boronitride, transition metal chalcogenide and graphene, we can construct atomically thin novel quantum structures. Unlike conventional semiconductor heterostructures, charge transport in of the devices is found to critically depend on the interlayer charge transport, electron-hole recombination process mediated by tunneling across the interface. We demonstrate the enhanced electronic optoelectronic performances in the vdW heterostructures, tuned by applying gate voltages, suggesting that these a few atom thick interfaces may provide a fundamental platform to realize novel physical phenomena. In this presentation, we will discuss several recent development of electronic and optoelectronic properties discovered in the van der Waals heterostructures, including hydrodynamic charge flows, cross-Andreev reflection across the quantum Hall edges states, and interlayer exciton formation and manipulations.
Speaker: Dr. Philip Kim (Harvard University)
Friday, October 27, 2017
Time: 12pm - 1pm
Location: EACSB 1.106 (Edinburg), BSABH 1.104 (Brownsville)
Towards Violation of Classical Inequalities using Quantum Dot Resonance Fluorescence
With their atom-like properties, semiconductor quantum dots have attracted considerable interest recently, ranging from fundamental studies of quantum optics to advanced applications in the field of quantum information science. In this talk, we will discuss some experimental progress towards the understanding of light-matter interactions that occur beyond well-understood monochromatic resonant light scattering processes in semiconductor quantum dots. First, we will describe the measurements of resonance fluorescence under bichromatic laser excitation. Under these conditions, the scattered light exhibits a rich spectrum containing many spectral features that lead to a range of nonlinear multiphoton dynamics. Second, we will present about the light scattered by a quantum dot in the presence of spectral filtering. Finally, Franson-interferometry will be discussed using spectrally filtered light from quantum dot resonance fluorescence which paves the way for producing single time-energy entangled photon pairs that could violate Bell's inequalities.
Speaker: Dr. Manoj Peiris (The University of Texas Rio Grande Valley)
Friday, November 3, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
Multimessenger astronomy for Core Collapse Supernovae
In this talk I will review the astrophysics ingredients, theoretical and observational, for studying Core Collapse Supernovae with Gravitational Waves, Neutrinos and EM observations. Particular focus will be devoted to the landscape of morphologies of the expected GW signals as well as SN dedicated GW detection methodologies.
Speaker: Dr. Michele Zanolin (Embry Riddle Aeronautical University)
About the speaker: Michele Zanolin holds a PhD in Physics from the University of Parma (Italy), was a visiting scholar and Post Doctoral Associate at MIT between 1999 and 2007, and faculty member at Embry Riddle since 2007. Michele Zanolin is the PI of the ERAU LIGO group, who has been acting as Supernova group liaison since Dec 2014.
Friday, November 10, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
Growth and Characterization of Gallium Based Thin Films for Bio Sensors Applications
The properties of Aluminum Gallium Nitride (AlGaN), Gallium Nitride (GaN) and Gallium Oxide (GaO) thin films on different substrates are studied in this research. There have been great accomplishments for building layers of these materials for biosensors, opto-electronics and high power devices. A magnetron sputtering system is used to create the thin-films on silicon (Si), sapphire (Al2O3) substrates. The electrical characteristics and the surface morphology of the thin films are investigated by using a X-ray photo electron spectroscopy, a scanning electron microscopy and an atomic force microscopy. The methodology to fabricate the wide band gap (WBG) semiconductor thin films at lower pressure with better crystal quality is still challenging.
Speaker: Dr. Hasina Huq (The University of Texas Rio Grande Valley)
About the speaker: Dr. Hasina F. Huq is an Associate Professor and the Graduate Program Coordinator in the Department of Electrical Engineering at the University of Texas Rio Grande Valley. Dr. Huq received her M.S. degree in Electrical Engineering from the Virginia Polytechnic Institute and State University and had her Ph.D. in Electrical Engineering from the University of Tennessee, Knoxville. Her teaching and research interests include electronics, wide-bandgap semiconductor devices, and VLSI system design. Her research work in these areas has been published widely in peer-reviewed journals/conference proceedings (more than fifty research papers/book chapters). Dr. Huq is currently the director of the ‘Sputtering System Research Laboratory (SSRL)’ at UTRGV.
Friday, November 17, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
Hot nanophotonics: From hot carriers to hot thermal emitters
Nanophotonics has enabled extreme control on the flow of light leading to revolutionary applications including imaging, and chemical sensing. Not only does nanophotonics allow the extreme control on light flow, but also on heat flow. The interplay between light and heat at the crossroads of nanophotonics leads to many promising applications in energy conversion. In this talk, I will describe devices that allow efficient renewable energy harvesting by achieving extreme anisotropy and asymmetry. First, I will discuss how hot carriers – commonly considered loss pathways in plasmonic devices – can convert low energy photons to higher energies. This new upconversion scheme promises to be broadband, tunable, and an order of magnitude more efficient than existing solid-state upconversion schemes. Next, I will describe a renewable energy harvesting device based on nanophotonic selective thermal emitters. I will show how semiconductor nanostructures enable high efficiency waste heat recovery. Finally, I will show how thermal emitters based on extremely anisotropic materials – carbon nanotubes – can revolutionize heat to electricity conversion. The extreme control on light and heat flow would open new avenues for addressing one of the greatest technological challenges of our time – providing clean energy to the world.
Speaker: Dr. Guru Naik (Rice University)
About the speaker: Gururaj (Guru) Naik is an assistant professor at Electrical & Computer Engineering, Rice University since this fall. Previously, he was a post-doctoral scholar in the Dionne group at Stanford University. He received an M.E. from the Indian Institute of Science, India and a PhD from Electrical & Computer Engineering, Purdue University. During his PhD, he developed new plasmonic materials for nanophotonic applications. His research interests lie in the application of nanophotonic principles for energy, imaging and health. Guru is a recipient of IEEE Photonics Society Graduate Student Fellowship, an Outstanding Graduate Research award from Purdue University and a Gold Medal from the Indian Institute of Science.
Friday, December 1, 2017
Time: 12pm - 1pm
Location: BSABH 1.104 (Brownsville), EACSB 1.106 (Edinburg)
Plasma Physics using Particle-in-Cell Simulations: Applications to Space and Laboratory
Particle-in-cell (PIC) simulations are widely used tools to study plasmas and their interaction with the electric and magnetic fields. Because PIC codes directly solve the fundamental equations: relativistic Newton’s equations + the Maxwell equations, the simulations can describe the plasma behavior more accurately than any other codes. In this colloquium, I will talk about the astrophysical and the laboratory applications of PIC simulations: (1) collisionless shocks, (2) magnetic reconnection, (3) laboratory astrophysics, and (4) laser based ion acceleration. These are different subjects but are related by sharing the same goal, “particle energization”. Collisionless shocks are generated by interactions between fast moving plasma flows. In collisionless shocks, I will explain under what processes the electrons and the protons are accelerated [Park et al. PRL 114, 085003 (2015)]. Magnetic reconnection is a topological rearrangement of the magnetic field where the flux-freezing breaks down. I will present how the electrons are accelerated in magnetic reconnection to explain the observed electron spectrum in solar flares. Finally I will introduce some laboratory applications of PIC simulations. I will present our recent progress to find a collisionless shock in the laboratory experiment. Also, I will talk about our recent simulation and experimental studies of laser driven ion acceleration done in LBNL.
Speaker: Dr. Jaehong Park (Lawrence Berkeley National Laboratory)
About the speaker: Jaehong Park is postdoctoral fellow at Lawrence Berkeley National Laboratory, California, since 2017. Previously, he was a postdoctoral researcher at Princeton University, New Jersey, in 2013 – 2017. He received a PhD in plasma physics and astrophysics at University of Rochester, New York in 2013. He developed simulation code to study particle acceleration in space and astrophysics. Also he has participated in the exascale computing project for developing particle-in-cell codes.