February 25, 2014
Luis Ho,
Kavli Institute for Astronomy and Astrophysics
Host:
Wei-Hao Wang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Black Holes Big and Small:
Impact on Galaxy Formation
Abstract
Supermassive black holes (BHs) have been found in almost 100 galaxies by dynamical modeling of spatially resolved kinematics. The Hubble Space Telescope revolutionized BH research by advancing the subject from its proof-of-concept phase into quantitative studies of BH demographics. Most influential was the discovery of a tight correlation between BH mass and velocity dispersion of the bulge component of the host galaxy. Together with similar correlations with bulge luminosity and mass, this led to the widespread belief that BHs and bulges coevolve by regulating each other's growth. I present a major update to the status of this field. I will discuss (1) how BH mass correlates tightly only with classical bulges and ellipticals, (2) how the zero point and slopes of the fundamental correlations need to be revised, (3) BH mass estimates in quasars, (4) the discovery of intermediate-mass BHs in dwarf galaxies and implications for quasar seeds, (5) quasar-mode energy feedback at high redshifts, and (6) the evolution (or lack thereof) with time of the BH-host galaxy scaling relations.
Brief Bio
Luis C. Ho has worked on a wide range of topics on astronomy and astrophysics, including surveys for active galactic nuclei, physics of quasars and active galaxies, searches for supermassive black holes, origin of the Hubble sequence, star clusters, supernovae, interstellar medium, and extragalactic star formation. His research employs multiwavelength observations on all scales, from radio waves to X-rays, using a suite of ground-based facilities and space-based missions. He has published almost 500 papers, including 300 in refereed journals. Luis was educated at Harvard University and U. C. Berkeley, and for the past 15 years he has been Staff Astronomer at the Observatories of the Carnegie Institution for Science. Beginning in 2014, he has taken the positions of Director of the Kavli Institute for Astronomy and Astrophysics (KIAA), Chair Professor in the School of Physics at Peking University, and Distinguished Research Fellow of the Chinese Academy of Sciences. He also serves as the Associate Editor of the Astrophysical Journal Letters.
Slides
March 4, 2014
Yee Bob Hsiung,
National Taiwan University
Host:
Jiwoo Nam
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
The Elusive Neutrinos – Neutrino Oscillation,
Mixing and Mass Hierarchy
Abstract
The tiny, nearly massless neutrinos have been one of the most elusive particles in elementary particle physics in the past several decades. In this talk I will review the experimental phenomena on the neutrino oscillation, mixing and mass hierarchy, as well as the recent new results from Daya Bay reactor neutrino experiment with spectral measurement.
The discovery of non-zero θ13 in 2012 and the unexpected large sin22θ13 has encouraged studies of the potential to resolve mass hierarchy such as the proposed JUNO experiment. In this talk, I will describe the Daya Bay experimental design, installation, calibration and data analysis. Together with updates on the current results and status of Daya Bay, I will also give a brief introduction to some potential future developments relevant to the Daya Bay experiment.
Brief Bio
Prof. Yee Bob Hsiung received his Bachelor degree at NTU Physics Department and Ph.D. in Physics at Columbia University. He has been working on experiments of discovering direct CP violation in neutral kaon decays and rare K and B-meson decays, as well as LHC-CMS experiment to search for new physics for many years, and in recent years on Daya Bay neutrino oscillation experiment discovering 3rd mixing angle. He was the co-spokesperson of KTeV experiment at Fermilab before he returned to NTU in 2002. He received the Outstanding Scholar Awards from the Foundation for the Advancement of Outstanding Scholarship (2003-2008), and was the physics department chair (2007-2013) and the President of PSROC (2012-2014). Recently he has received the 17th National Professorship of ROC in Taiwan from Ministry of Education (2014-2017).
Slides
March 11, 2014
Wen Yih Isaac Tseng,
National Taiwan University
Host:
Shi-Wei Chu
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Application of Diffusion MRI to Cancer, Heart,
and Brain Connectome Imaging
Abstract
Diffusion MRI is a technique that allows us to measure the translational motion of the water molecules. The technique entails application of a pair of strong and brief magnetic gradients to phase-encode the positions of water molecules from which the displacement probability of water diffusion can be estimated. Since the technique often requires multiple measurements with different gradient strengths and directions, the scanning often last for hours using conventional MRI pulse sequences such as the spin echo sequence. Such long scan time prohibits the application of diffusion MRI to clinical patients. It was not until the ultrafast imaging technique, called echo planar imaging, became a standard package in the clinical scanners in the early 90's, clinical application of diffusion MRI started to be feasible. The first clinical value of diffusion MRI is the detection of acute stroke. It has become a routine examination to diagnose acute stroke especially in the emergency practice. With the improvement of the diffusion techniques, diffusion MRI has been successfully applied to many other diseases. Diffusion MRI is extremely sensitive to cancerous tissue because the water diffusion is restrictive in a tissue that contains high cell density or tortuous interstitial space. Therefore, the mean diffusivity of the cancerous tissue is relatively lower than that of the normal tissue. We have used diffusion tensor imaging (DTI) to serve as a screening tool for patients who are suspected to have prostate cancer and are scheduled to receive trans-rectal ultrasound biopsy. DTI shows high sensitivity and high negative predictive value when it is compared with the biopsy results. Diffusion MRI can equally reveal the well-organized myocardial fiber architecture in a normal heart. The technique has been applied to patients with myocardial disease such as hypertrophic cardiomyopathy or myocardial infarction. It shows how the myocardial fiber architecture is altered in these diseases and their functional consequences under such alteration. Advanced diffusion MRI techniques such as diffusion spectrum imaging not only reveal the fiber tract bundles in the brain, but also evaluate the integrity of the white matter tracts. Such information points to the soundness of white matter connection in the brain circuitry, and so diffusion EPI could potentially provide objective evidence for the diagnosis of mental disorders such as schizophrenia. In conclusion, recent progress in diffusion MRI has proved its potential clinical values. The future direction would be the improvement of gradient performance to achieve better image quality and shorter scan time. In addition, it is imperative to develop user-friendly software for efficient management, calculation and visualization of the diffusion MRI results.
Brief Bio
Doctor Wen-Yih Tseng graduated from Department of Nuclear Engineering in National Tsing Hua University, then studied Post-baccalaureate Medicine Department in National Taiwan University. After five years of doctor life, he went abroad to Massachusetts Institute of Technology to finish his Ph. D in Nuclear Engineering, and post doc research in MGH-NMR Center, Harvard Medical School. His research interests include magnetic resonance in cardiovascular imaging, neuroimaging and cancer imaging, diffusion and perfusion MRI techniques and application to clinical studies. Now he is an attending doctor in Department of Medical Imaging in National Taiwan University Hospital, and also a professor in Center for Optoelectronic Medicine in National Taiwan University College of Medicine.
Slides
March 18, 2014
Phil Marshall,
Stanford University
Host:
Yen-Ting Lin
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Measuring Distance in the Universe
with Gravitational Lenses
Abstract
Understanding the mysterious "Dark Energy" that appears to be driving the expansion of the Universe is one of the biggest challenges facing cosmologists today. While offering no new physical understanding, I will describe a method for at least quantifying the effect of the dark energy that is both new and old: the time delays between the multiple images of gravitationally lensed AGN have long been known to enable a measurement of the Hubble constant, but we have only recently shown how, with careful modeling of enough high quality data, we can achieve comparable accuracy to other, better known cosmographic probes. After introducing and describing this experiment in some detail, I will discuss how we plan to build on it in the next decade, using new lenses discovered using the Large Synoptic Survey Telescopes to find and measure large numbers of suitable systems.
Brief Bio
Phil Marshall is a research scientist at SLAC national accelerator laboratory. He did his PhD at the Cavendish Laboratory in Cambridge, UK, on Bayesian inference and clusters of galaxies. He was one of the founding postdocs at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford, where he began thinking about strong gravitational lenses, their applications in galaxy evolution and cosmology, and how to find more of them in wide field imaging surveys. He has been chair of the LSST strong lensing science collaboration since 2006, during which time he has been TABASGO Fellow at the University of California, Santa Barbara, Kavli Fellow at KIPAC, and Royal Society university research fellow at Oxford. Phil is now working on developing science analyses for LSST, among many other things.
Slides
March 25, 2014
Yang-Fang Chen,
National Taiwan University
Host:
Yuan-Huei Chang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Design, Fabrication, Characterization
and Application of Semiconduction
Nanocomposites
Abstract
Hybrid nanocomposites consist of multi-component nanomaterials with an appropriate design enable to generate unprecedented properties and multi-functionalities, which can not be found in one single component material. This talk will present some of our recent works in this research field. Based upon the collaboration with several outstanding scholars, by the integration of zero and one dimensional semiconductors having a suitable band alignment, photodetectors with ultrahigh sensitivity and wide spectral response have been developed. A new composite solar cell structure consisting of semiconductor nanoparticles and nanotips has been designed. It is found that the solar cell efficiency can be greatly enhanced due to the effects of photon down-conversion and light trapping. A new physical phenomenon named light fountain has been discovered based on the combination of semiconductor nanowires and photonic crystals. A novel composite device made with liquid crystals and semiconductor nanowires has been created. This new-device possesses a unique feature in that the polarization of the emission from semiconductors can be fine tuned by an external bias. Finally, a graphene-insulator-semiconductor MISLED has been developed, which shows a tunable electroluminescence spectra with the underlying mechanism different from the conventional p-n junction model.
Brief Bio
Prof. Yang-Fang Chen received his Bachelor degree at National Tsin-Hua University Physics Department and Ph.D. in Physics at Purdue University. He held the post-doctoral fellowship at Harvard University from 1985 to 1986. Now he is a Distinguished professor and Chair professor of National Taiwan University. He has been working on experiments of designing, fabricating and characterizing novel nanocomposite materials to discover new physical phenomena, semiconductor nanoscale devices with novel optoelectronic properties. He received of the Outstanding Research Award of National Science Council of ROC many times, and was the Distinguished research fellow of National Science Council of ROC from 1998 to 2004. Recently he has received the Academician of Asia Pacific Academy of Materials in 2013.
Slides
April 1, 2014
Chao-Lin Kuo,
Stanford University
Host:
Yen-Ting Lin
Time: 2:20 pm -3:20 pm
Place: Room 204, CCM-New
Phys. building
Title:
BICEP2 Results, Implications, and Future
Abstract
The BICEP2 team has just announced the detection of degree-scale B-mode polarization of the CMB, consistent with the imprint of inflationary gravitational waves. r=0 model is ruled out at very high significance. BICEP2 is the second generation in the BICEP/Keck series of small refractor experiments. I will discuss the immediate prospect of confirming and expanding BICEP2's discovery by Keck Array and BICEP3. A dedicated program that covers more sky can significantly reduce the uncertainties on tensor amplitude, putting models of inflation to further test.
Brief Bio
Prof. Chao-Lin Kuo received his Bachelor degree from NTU Physics Department in 1994 and Ph.D. in Astrophysics from U.C. Berkeley in 2003. After a postdoctoral fellowship at Caltech/JPL, he is currently Assistant Professor of Physics at Stanford University and SLAC. Prof. Kuo studies the polarization of the most ancient light, the Cosmic Microwave Background (CMB) radiation, emitted when the universe was in its infancy. The polarization in the CMB contains information on the birth of the universe (big bang/inflation), as well as its subsequent evolution.
Prof. Kuo is involved in both cosmological interpretation and instrumentation/technology development, focusing on experiments including BICEP/BICEP2/Keck Array/POLAR Array. He is an expert in advanced experimental techniques, such as cryogenics, superconductivity, and micromachining, for maximizing detector sensitivity to the faint CMB signal. Prof. Kuo has been awarded an Alfred P. Sloan Research Fellowship in 2009, an MRI (Major Research Instrumentation) grant in 2010, and an NSF Faculty Early CAREER Award in 2011.
Slides
April 8, 2014
Ssu-Yen Huang,
National Taiwan University
Host:
Yuan-Huei Chang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Charge, Spin, and Heat Transport in the
Proximity of Metal/Ferromagnet Interface
Abstract
Heat dissipation and exploitation of heat current are important topics in high-density electronics and emerging technologies. The study of the heat current, spin current, and charge current is called spin caloritronics. Spin Seebeck effect (SSE), which generates pure spin current from heat current and which is detected as charge current, is one of the key phenomena in spin caloritronics. The observation of SSE has been reported in ferromagnetic metals, semiconductors, as well as insulators by using transverse and longitudinal geometries with in-plane (∇xT) and out-of-plane temperature (∇zT) gradient, respectively. The mechanism of SSE has evolved from intrinsic difference in the spin chemical potentials to magnon-phonon interaction. However, recent studies show in the transverse geometry (∇xT) when ferromagnetic thin films are used on substrate, the SSE suffers the complications of the anomalous Nernst effect. Whereas in the longitudinal geometry (∇zT) when ferromagnetic insulator is used, one encounters a different issue of magnetic proximity effects (MPE) in the spin current detect layer. In this talk, I will first introduce the two geometries and discuss methods to circumvent these obstacles.
Brief Bio
Prof. Ssu-Yen Huang is an assistant professor in the Department of Physics at National Taiwan University. After receiving his Ph. D. in Electrophysics from National Chiao Tung University in 2009, he worked as a post doc research fellow subsequently at Academia Sinica, National Tsing Hua University, Massachusetts Institute of Technology, and Johns Hopkins University. He is an experimentalist in condensed matter physics and his current research focuses on Spintronics, including the spin-dependent thermal transport, spin injection into heterostructures, and the interplay of superconductivity and magnetic ordering.
Slides
April 22, 2014
Guang-Yu Guo,
National Taiwan University
Host:
Yuan-Huei Chang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Spin Hall Effect
Abstract
Spin Hall effect (SHE) refers to the generation of transverse spin current in nonmagnetic solids by an applied electric field due to relativistic spin-orbit coupling. Spin current generation, detection and manipulation are three key elements of the emerging spintronics. Large room temperature SHE not only provides dissipationless spin current but also is used to probe spin current and to drive magneto-electronic devices with little power consumption. Recent intensive research on SHE has also led us to such topical fields as topological insulators and spin caloritronics. In this talk, I will first give an overview on SHE. This will be followed by a presentation of my own theoretical investigations on SHE, including Berry phase theory and ab initio relativistic band structure method [1,2], large intrinsic SHE in metals [2-3] and gigantic SHE due to multi-orbital Kondo effect in gold with iron impurities [4-5].
[1] G. Y. Guo, Y. Yao and Q. Niu, Phys. Rev. Lett. 94, 226601 (2005);
[2] G. Y. Guo, S. Murakami, T. W. Chen, and N. Nagaosa, Phys. Rev. Lett. 100, 096401 (2008);
[3] G. Y. Guo, J. Appl. Phys. 105, 07C701 (2009) ;
[4] G. Y. Guo, S. Maekawa, and N. Nagaosa, Phys. Rev. Lett. 102, 036401 (2009);
[5] B. Gu, J.-Y. Gan, N. Bulut, T. Ziman, G. Y. Guo, N. Nagaosa and S. Maekawa, Phys. Rev. Lett. 105, 086401 (2010).
Brief Bio
Guang-Yu Guo is a distinguished professor in NTU Physics Department. He owned his PhD in Physics from Cambridge University in 1987. He joined the NTU Physics Faculty in 1998 after working in Daresbury Laboratory, UK for eleven years as a postdoctoral researcher, higher and senior staff scientist. He also worked in National Chengchi University as a chair professor and the founding director of the Graduate Institute of Applied Physics during 2009-2013. He has been fruitfully conducting theoretical research in condensed matter and materials physics in the past twenty-seven years, publishing over 200 journal papers with total citations of about 4000 and h-index of 35. He has received several academic awards and honors including the National Science Council Outstanding Research Awards (1998, 2004, 2009) and the Ministry of Education 57th Academic Award (2013). He is an elected Fellow of the PSROC (2005), the APS (2005) and the Institute of Physics (UK) (2013).
Slides
April 29, 2014
Tsun-Hsu Chang,
National Tsing Hua University
Host:
Yuan-Huei Chang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
How a Wave Packet Propagates at a
Speed Faster than the Speed of Light:
A superluminal mechanism with high
transmission and broad bandwidth
Abstract
The findings that we are going to present do not violate the special relativity and the causality. It gives us a chance to gain better understanding about the wave nature. A wave packet propagating with a group velocity faster than the speed of light is called the superluminal effect. It is generally attributed to anomalous dispersion and tunneling. The two mechanisms just mentioned suffer from the problems of narrow bandwidth and extremely low transmission. Here, we propose a new mechanism by employing the modal and interference effects to induce broadband superluminality with high transmission. An electromagnetic wave packet is generated and its characteristics are measured. The controllability on the group velocity, transmission, and bandwidth will be demonstrated. These findings arouse the interest of searching for the theoretical limit of the transmission and might facilitate applications in communication.
Brief Bio
Professor Tsun-Hsu Chang received his Ph.D. degree from National Tsing Hua University under the supervision of Prof. Kwo-Ray Chu. He has been working on the generation of high-power terahertz radiation based on the electron cyclotron maser. In addition, Prof. Chang also employ the microwave energy to interact with various advanced materials and found many interesting phenomena, such as much shorter processing time and much lower annealing temperature. His abilities to excite and control the electromagnetic modes enable him to study the wave nature such as superluminality and creates various industrial applications. He holds more than 35 patents. He received Young Faculty Research Award (2005), International Inventor Prize (2011), and seven consecutive years (2007-2013) of NTHU Excellent Research Award. He served as the vice-chair of the physics department for four years (2008-2012) and has taken the position of Chairman for Interdisciplinary Program of Sciences since February 2013.
Slides
May 6, 2014
George Barbastathis,
MIT
Host:
Chia-Lung Hsieh
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Compressive Phase Retrieval
Abstract
Compressive sensing is a class of image recovery techniques utilizing sparsity priors to recover undersampled signals with high fidelity. This talk is about compressive sensing as it applies to phase retrieval: interferometric and non-interferometric. For interferometric techniques, also known as “digital holography,” I will describe how to localize sparse objects, such as vibrating whiskers and particles in multi-phase flows, with sub-pixel accuracy. For non-interferometric techniques, I will discuss in particular the use of intensity priors in the “transport of intensity equation” method, where the phase is obtained by analogy to a lateral pressure potential in a compressible flow. Transport of intensity is especially interesting in the x-ray regime, where standard interferometry is difficult because common sources are spatially partially coherent and beam splitters-combiners are not available; as a concluding example, I will show how the sparsity prior of quasi-constant object density allows successful x-ray phase recovery despite the low coherence.
Brief Bio
George Barbastathis received the Diploma in Electrical and Computer Engineering in 1993 from the National Technical University of Athens and the MSc and PhD degrees in Electrical Engineering in 1994 and 1997, respectively, from the California Institute of Technology (Caltech.) After postdoctoral work at the University of Illinois at Urbana-Champaign, he joined the faculty at MIT in 1999, where he is now Professor of Mechanical Engineering and holds the Singapore Research Professorship in Optics. During the academic year 2013-2014 he is on sabbatical leave at the University of Michigan - Shanghai Jiao Tong University Joint Institute (上海交通大學密西根大學學院) in Shanghai, People's Republic of China. He has worked or held visiting appointments at Harvard University, the Singapore-MIT Alliance for Research and Technology (SMART) Centre, and the National University of Singapore. His research interests are three-dimensional and spectral imaging; phase estimation; and gradient index optics theory and implementation with subwavelength-patterned dielectrics. He is a membrane of the Institute of Electrical and Electronics Engineering (IEEE), the American Society of Mechanical Engineers (ASME) and in 2010 he was elected Fellow of the Optical Society of America.
Slides
May 13, 2014
Naoki Yoshida,
University of Tokyo
Host:
Yen-Ting Lin
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
The Dark Ages of the Universe
Abstract
One of the milestones in the cosmic history is the formation of the first generation of stars and hydrogen reionization. The standard theory of cosmic structure formation predicts that the first stars were born about a few hundred million years after the Big Bang. The dark Universe was then lit up once again, and eventually filled with ultraviolet photons emitted from stars and galaxies. Recent astronomical observations discovered distant galaxies and super-massive blackholes that were in place when the age of the universe was less than one billion years old. How were the galaxies formed, and what are the origin of the massive blackholes ? The key to these interesting question lies probably in the formation of the first stars. I present the results from super-computer simulations that follow self-consistently the formation of protostars through to the early stages of a main-sequence star with thermonuclear burning. The characteristic mass of the first stars is estimated from such simulations. I discuss implications for the formation of early blackholes and Galactic metal-poor stars. Finally I propose to use future wide-field infrared surveys to detect the supernova explosions of the first stars.
Brief Bio
Born in Kobe, Japan.
PhD in 2002, Max-Planck-Institute for Astrophysics.
Postdoc at Harvard, then positions at Nagoya-University and IPMU.
Now professor at U-Tokyo and at Kavli IPMU.
Prof. Yoshida is a world renown astrophysicist, with specialty in large scale numerical simulations. He obtained his Ph.D. from University of Munich in 2002. After a postdoctoral fellow position in Harvard, he held faculty positions at Nagoya University, Kavli Institute for the Physics and Mathematics of the Universe, and the University of Tokyo. He has won the Young Scientist Award from both Astronomical Society of Japan and International Union of Pure and Applied Physics. Prof. Yoshida's recent research has focused on the formation of first generation of stars in the Universe, and the nature of dark matter.
Slides
May 20, 2014
Phil Armitage,
University of Colorado, Boulder
Host:
Yen-Ting Lin
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Formation and Discovery of Extrasolar
Planetary Systems
Abstract
The discovery of several thousand extrasolar planets allows us to assess, for the first time, whether the Solar System is a typical outcome of the planet formation process. I will review the current status of exoplanet observations, and their implications for the theoretical understanding of how terrestrial and gas giant planets form. Observations suggest that the early evolution of many planetary systems is surprisingly violent, and I will argue that this implies the existence of a new, as yet unidentified, class of terrestrial planets. At earlier times the formation mechanism of the first asteroid-sized bodies remains unknown, and I will discuss recent progress toward resolving this mystery.
Brief Bio
Professor Armitage is a Fellow of JILA and a professor in the Department of Astrophysical and Planetary Sciences at the University of Colorado, Boulder. Born in the UK, he has B.A. and Ph.D. degrees in physics and astrophysics from the University of Cambridge. His research in theoretical and computational astrophysics focuses on the environment of planet formation within protoplanetary disks, the physics of planet formation, and the dynamics of extrasolar planetary systems.
Slides
May 27, 2014
Shangjr Gwo,
National Tsing Hua University
Host:
Chia-Lung Hsieh
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
Low-Loss, Active Plasmonics Based on
Novel Silver Macro-, Meso-, and Nanostructures
Abstract
Surface plasmon polaritons (SPPs) supported on noble-metal surfaces possess larger wavevectors than that of light at the same frequency from the visible to the infrared frequency range. Therefore, noble-metal nanostructures can function as near-field transducers to compress light below the diffraction limit and to realize diffraction-unlimited applications such as plasmonic nanoantennas, nanolasers, and nanocircuits. However, the real-world applications of SPPs are very sensitive to plasmonic losses. Recently, several works, including our own, have demonstrated that ultrasmooth and single-crystalline silver epifilms as well “giant” colloidal crystals exhibit lowest plasmonic losses. Here, I will present some important applications based on these novel silver macro, meso-, and nanostructures, including ultralow-threshold and all-color plasmonic nanolasers, as well as uniform surface-enhanced Raman spectroscopy (SERS) substrates for quantitative single-molecule sensing. In combination with the focused ion beam milling technique, we can also fabricate high-quality plasmonic nanocavities, nanocircuits, and nanoantennas on these colloidal Ag crystals. By incorporating III-nitride semiconductor nanostructures as local coherent SPP sources (spasers) into these plasmonic structures, low-loss, active integrated plasmonic systems can become reachable in the near future.
Brief Bio
Professor Shangjr Gwo received his Ph.D. degree from the University of Texas at Austin. His researches are focused on low-dimensional, atomic-scale to nanometer-scale condensed matter systems, mainly based on semiconductor epitaxial materials. In addition, Prof. Gwo has been working on epitaxial studies of commensurately matched indium nitride (InN), gallium nitride (GaN), aluminum nitride (AlN), including heterojunctions, quantum wells, quantum dots, self-aligned nanorods, and quantum disks in nanorods. Also, he is interested on optical spectroscopy, nanofabrication, and electronic structures of III-nitride surfaces and interfaces. He received Outstanding Research Award, National Science Council (2000, 2004), and Ten Outstanding Youths in Taiwan (2001). Now he is an professor in Department of Physics in National Tsing Hua University.
June 3, 2014
Cliff Burgess,
McMaster University
Host:
Chi-Te Liang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
What is the Universe Made Of?
The Case for Dark Matter and Dark Energy
Abstract
For the first time in human thought it is now possible to observationally determine how much matter is in the Universe as a whole. These observations strongly support the “Concordance Model” of Hot Big Bang Cosmology, and reinforce earlier indications that ordinary matter (atoms, nuclei and electrons) make up at present at most 4% of the total of the Universal energy density. The big surprise was that the rest consists of “two” kinds of unknown forms of matter: the so-called Dark Matter and Dark Energy. This talk summarizes for the various lines of evidence for their existence, and some of the theoretical ideas which have been proposed to account for their properties. It closes with my personal assessment of which is most likely to be the right description, given what we know now.
Brief Bio
Cliff Burgess was born in Manitoba and was raised in various places around Western Canada, Ontario and Europe. He received his B.Sc. in a co-op programme, with a joint honours in Physics and Applied Math from the University of Waterloo. Cliff Burgess did his doctoral work in Theoretical Particle Physics at the University of Texas in Austin under the supervision of Steven Weinberg.
After doing a short postdoctoral stint at the Institute for Advanced Study in Princeton, in 1987 Cliff Burgess joined the faculty at McGill University, where he was made James McGill Professor in 2003. Cliff Burgess is presently a professor with McMaster University’s department of Physics and Astronomy and is an Associate Faculty Member at Perimeter Institute for Theoretical Physics. Prof. Burgess has spent sabbatical years with the Institute for Advanced Study in Princeton as well as the University of Neuchatel and CERN in Switzerland.
Prof. Burgess was a Killam Fellow from 2005 – 2007 and elected a Fellow of the Royal Society of Canada in 2008. He received the Canadian Association of Physicists/Centre de Recherches Mathematiques (CAP-CRM) prize for theoretical physics in 2010.
Slides
June 10, 2014
Shin Nan Yang,
National Taiwan University
Host:
Kwo-Ray Chu
Time: 2:20 pm -3:20 pm
Place: Room 104, CCM-New
Phys. building
Title:
How Physics Comes to Sing
in Mathematical Tune
Abstract
我們現在都已習以為常地接受科學的法則、定律應該可以數學形式表述，尤以物理為然。對物理的理論架構我們不僅要求其數學的嚴謹性，也要求它要全盤一致，即自洽性。這樣的巨塔當然不是一天可以造成，而是在約四千年的歷史進程中，經由許多智者接續努力建造而成的。在本演講中，我將概述自巴比倫時期開始，逐步讓人類得以確立以數學語言來解開自然奧秘的過程。
That any scientific law and theorem should be expressible in mathematical terms is nowadays taken for granted. This is especially true in physics, where any theory is required to be mathematically complete and self-consistent. Such a high level of sophistication, of course, is not achieved in one day, but rather via the consecutive efforts of many great scientists over the 4,000 years of history. In this talk, I’ll elaborate and recount the seminal developments which led mathematics to become the language of all physical theories, starting from the Babylonian period chronologically.
# Note: The talk will be presented in Chinese.
Brief Bio
楊信男
台大物理系畢業，美國紐約州立大學石溪分校物理博士。其後在 Brookhaven National Laboratory 及 University of Washington (Seattle) 擔任博士研究員。回國後任教於台大物理系，一直從事於理論核及強子物理方面的研究。為美國物理學會和中華民國物理學會會士。
Professor Shin Nan Yang received his Bachelor degree from NTU Physics Department and Ph.D. in Physics from State University of New York at Stony Brook. After postdoctoral work at Brookhaven National Laboratory and University of Washington (Seattle), he came back to join the faculty at NTU Physics Department. His research focuses on theoretical nuclear and hadron physics. He is also an elected Fellow of the PSROC (2003) and the APS (2002).
Slides