Institute of Physics

The Institute of Physics was founded in Shanghai in 1928. It was re-established in Taiwan in 1962 with Dr. T.Y. Wu as its first director. Succeeding directors were: Drs. W. N. Wang (1976-1977), E. K. Lin (1977-1989), L. T. Ho (acting, 1989-1990), and T. T. Tsong (1990-present).

In 1966, together with Tsing-Hua University and Taiwan University, the Institute organized the Physics Research Center under the auspices of the National Science Council. In 1970, an interdisciplinary research program for atmospheric science and fluid mechanics was initiated in the Institute of Physics. In 1975 the biophysical research program was set up. During Academia Sinica's first five-year plan (1981-1985), the Institute's scope expanded to include theoretical physics, covering mainly high energy physics, nuclear physics, and statistical mechanics.

The original two-story Institute building was replaced by the present one in April 1983. Since the beginning of the second five-year plan (starting 1986), the Institute has continued to grow, both in research staff and facilities. Presently, the Institute conducts research in areas including theoretical physics, nuclear physics, experimental high energy physics, condensed matter and surface physics, biophysics, and fluid and non-linear mechanics.

RESEARCH

THEORETICAL PHYSICS

• Gauge Theories.
• Particle Phenomenology.
• Strings, Integrable System and Gravity.
• Cosmology.
• Static Critical Phenomena.
• Dynamic Critical Phenomena.
• Chaos and Nonlinear Dynamics.
• Computational Algorithms.
• Condensed Matter Theory.
• Theoretical Biophysics.

Near Field Microscope

NUCLEAR PHYSICS

• Nuclear Coulomb Excitation by Heavy Ion.
• Investigation of the Phenomena in Ion-Atom Collisions.
• Measurements of g-Transitions in Nuclei.
• Study on the Charged Particle Induced Nuclear Reactions.
• Application of Nuclear Techniques.
• Monte Carlo Simulations for Photon Detector Response.
• The Study of Hadronic Structure and Nuclear Force Based on Quark Bag Model.
• Quark Matter and Related Problems.
• Dark Matter and Nuclear Physics.
• Green's Function Method in Nuclear Many-Body Problems.
• Properties of Hypernuclei.
• Heavy Quark Effective Theory and Symmetry Breaking Effects.
• Nucleonic Strangeness.
• Semi-empirical Determination of the Properties of Nuclear Matter.

Experiment of External Beam PIXE

SOLID STATE PHYSICS AND BIOPHYSICS

• Surface Physics.
• Properties of Superlattice and Nanocrystallines.
• Synchrotron Radiation Application.
• Impurities in Semiconductors.
• Magnetic and Superconducting Phenomena.
• Physical Properties in Alloys.
• Enhanced Raman Scattering.
• Raman Spectrum of Non-linear Materials.
• Molecular Crystal Spectroscopy.
• Principles and Applications of Atomic Manipulations.
• Kerr Effect.
• Fluorescence of Biological Material and its Applica-tions.
• Mixed Valence Fluctuations.
• 1/f Noise.
• Diamond Films.

HYDRODYNAMIC AND ATMOSPHERIC PHYSICS GROUP

• Effects of Flow Shear and Wall on Vortex Shedding Behind an Obstacle.
• Effects of Turbulence Intensity on the Mean Flow Behind Two Cylinders.
• Mixing and Diffusion of Buoyant Jets.
• Flux-Vector-Splitting Scheme for Dilute Gas-particle JPL Nozzle Flow.
• Solutions to a General Forced Non-linear Oscillations Problem.
• Wake Instability and Control.
• Sonoluminescence.
• Bursting Dynamics of Soap Films.
• Polymer Conformation in Binary Solvent.
• Fluid in Porous Medium.

PERSONNEL AND FACILITIES

Scanning Tunneling Microscope

PERSONNEL

Currently the Institute has 1 distinguished research fellow, 23 research fellows, 7 associate research fellows, 6 assistants research fellows, 1 research assistant, 1 assistant, 10 visiting scholars, 22 postdoctoral research staff, 4 administrative staff, 4 technicians 8 temporary administrative assistants, 4 temporary technical assistants, and approximately 30 full-time research assistants.

FACILITIES

Library

Major facilities include an atomic force microscope, a UHV scanning tunneling microscope, a low energy X-ray detector, the system of electrolyte by AFM, a 3MV Tandem electrostatic accelerator, a 400 KeV positive ion accelerator, multi-channel analyzers, surface analysis systems, infrared spectrometers, Raman spectrometers, rotating anode high power X-ray diffractometer systems, closed cycle helium refrigeration systems, vibrating sample magnetometers, evaporating systems, sputtering systems, image process systems, continuous tracer analy-zers, and computer workstations. The library has over 30,000 books and monographs and subscribes to appro-ximately 300 periodicals.

MAJOR RESULTS OF RESEARCH

Testing a Gamma Detector

THEORETICAL PHYSICS

• Hu has found that the finite-size scaling functions of the existence probability Ep and the percolation probability P of percolation models depend sensitively on boundary conditions, definitions of percolating clus-ters, and lattice shapes. However, the critical point, critical exponents, and thermodynamic order para-meters calculated from Ep and P do not depend on such factors.
• Ziff considered that at Pc determined by cell-to-site renormalization group transformation (RGT), Ep is not equal to expected value (Phys. Rev. Lett. \E11;69, 2670, 1992) and there is some problem in RGT. Hu has pointed out that at Pc determined by cell-to-cell renormalization group transformation, Ep is equal to expected value and there is no problem in RGT.
• In 1984, Privman and Fisher (PF) proposed the idea of universal scaling functions and nonuniversal metric factors (Phys. Rev. 30, 322, 1984), which was not confirmed for about 20 years. Hu and his students have found that by choosing appropriate aspect ratios for each lattice and a very small number of nonuniversal metric factors, six percolation models on planar lattices have universal scaling functions (Phys. Rev. Lett. 75, 193, 1995).
• Hu has found that the probability Wn for the appearance of n, n = 1, 2,..., percolating clusters has very good scalingbehavior. Hu and his students have found that six percolation models on planar lattices have universal scaling functions for Wn. The values of Wn at critical point may be used to compare with experimental data of quantum Hall effects.

  Beamline System of 3MV Tandem Accelerator

• Hu and his co-workers have found the behavior of the distributions of zeros of the square lattice q-state Potts model (Phys. Rev. Lett. 76, 169 and 173, 1996).
• Hu and his co-workers have found that the critical point determined by cell-to-cell renormalization group transformations converges much more quickly than cell-to-site renormalization group transformations.
• Hu has pointed out that periodic boundary conditions in his paper are different from periodic boundary conditions in Hovi and Aharony's paper. Therefore, they have obtained different value of Ep at the critical point (Phys. Rev. Lett. 76, in press, 1996).
• Developed a new method of measuring the top quark mass through top di-lepton events.

  Static and Dynamic Light Scattering Equipment

• Pointed out that by measuring the ``lepton-correlated asymmetry,'' it is possible to observe the spin correlation of top and anti-top at the tevatron.
• Determined the parton spin distribution functions in a proton.
• Completed the studies of weak radiative decays of heavy hadrons, form factors of heavy mesons, nonfactorization effects on nonleptonic weak decays of heavy mesons.
• Completed the PQCD calculation on semi-leptonic de-cays of B meson.
• Developed a set of renormalized Ward Identities to handle the renormalization problem of chiral gauge full theories.
• We applied the previous developed hybrid algorithm to the optimization problems with external fields and studied the algorithm that could keep the computational time linear.
• We have calculated the production of primordial gravitational waves during inflationary epoch in the early universe.
• We studied the anisotropy and polarization of the cosmic microwave background.
• Finished a self-organized model of an earthquake and developed a model and experiment for studying surface cracks.
• Contributed to the CDF proton-antiproton collision experiment at Fermi National Accelerator Laboratory. Discovered and confirmed the existence of top quark in March 1996. We are presently studying its properties.

Experimental Setup for Studying Sonoluminescence

NUCLEAR PHYSICS

• Studied the feasibility of a full scale neutrino oscillation experiment.
• Studied ⁷Li-ion induced Coulomb excitation.
• Investigated reaction channels of ⁵¹V+⁷Li system below Coulomb barrier.
• Studied the H(d,r) ³He reaction using polarized deuteron beams at low energies.
• Studied L-shell X-ray production in rare earth elements by MeV ⁴He-ions.
• Studied charge-state dependence of M-shell X-ray production in Ho and K-shell X-ray production in Al by 2-12 MeV carbon ions.
• Completed backscattering studies of ⁷Li, ¹²C and ¹⁶O-ions at energies 3-15 MeV.
• Completed a PIXE study of vitrification of carnation in vitro culture.
• Continued to carry out Monte Carlo simulations of asymmetric Compton suppression spectrometer.
• Developed for the angular correlation measurement a unique technique for data normalization.
• Investigated the effect of the D excitation on the nucleon-nucleon effective interactions in the nuclear shell model.
• Studied Green's function method with energy-independent vertex functions.
• Investigated symmetry breaking effects in chiral dynamics of heavy mesons.
• Studied nucleonic strangeness and PP annihilation branching ratio.
• Studied the radiative weak decays of heavy hadrons.
• Investigated the effect of projectile shapes on cross sections and momentum distributions of fragments from heavy-ion reactions.
• Studied correlated finite temperature mean field approximation.

SOLID STATE PHYSICS AND BIOPHYSICS

• Discovered the ascending motion of step edge and in-layer atoms at Ir(001), (113) and (111) surfaces below or around 500K. This discovery will affect the future development of theories of surface atom energetics, crystal growth, and epitaxial growth of thin films.
• Achievements in temperature-modulation Raman Spectroscopy of triglycerine sulphate crystal.
• Achievements in crystal growth and temperature-modulation Raman Spectroscopy of Lithium Niobate crystal (LiNbO).
• Magnetic coupling study between radial and axial magnetic gears.
• Physical property study of LaNiC.
• Non-Markovian thermal relaxation at elevated tem-peratures.
• Infrared absorption spectrum of beryllium acceptors in silicon.
• Domain and domain wall study in Ni-Fe thin-film system.
• Magnetoimpedance study in amorphous ferromagnetic materials.
• Observed the quantum size effect in Pd nanocrystal.
• Set up a high-pressure resistance measurement system.
• Improved the accuracy of an existing micro-calorimeter to ± 2%.
• In the study of the growth mechanism of diamond films, highly oriented diamond films are grown by bias-pretreatment. We have grown highly oriented diamond films with different orientations by varying the growth temperatures and gas compositions on different subs-trates, such as Si, SiC, graphite.
• In the study of the relationship between the magnetic property and the crystal structure of single crystal metal films and superlattices, epitaxial Co, Cr, V, Mo single crystal films and superlattices have been grown by the MBE method. We have found that the in-plane or the out-of-plane magnetic anisotropy is closely related to its crystal structure and orientation.
• Observed quantum confinement effect on Pt(100) re-constructed surface by scanning tunneling microscopy (STM).
• Manipulated atom clusters on Au and Pt surfaces in nonconducting fluid by STM.
• Analyzed the surface structure of Si(100) by Kikuchi electron holography.
• Studied the surface structure of Si(111) with a mono-layer of Au by Kikuchi electron holography.
• We studied a reversible phase transition of one mono-layer of Pb on a Ge(111) surface near 180¢J using a scanning tunneling microscope.
• We studied the surface structures and structural trans-formations on a Pb/Si(111) surface.
• Completed the study of surface chemical inhomogen-eities of BiSrCaCuO high temperature superconductors synchrotron imaging spectromicroscopy.
• Completed the development and installation of an im-aging spectromicroscopy with sub-micron spatial reso-lution using synchrotron radiation.
• Study on the renal circulation.
• Completed the equation for the meridian and the primary experimental demonstration.

HYDRODYNAMIC AND ATMOSPHERIC PHYSICS GROUP

1996 Taipei International Symposium on Surfaces and Thin Films

• Experiment on bursting soap film.
• Preliminary experiments on sonoluminescence.
• Completed the study of effect of surface waves on a buoyant jet.
• Completed the numerical simulation of vertical forced plume in a crossflow of stably stratified fluid.
• Completed a turbulence modeling development and its applications on the prediction of turbulent complex shear flow.
• Applications of the radiative transfer model to atmo-spheric radiation and remote sensing problems.
• Atmospheric corrections of satellite sensing data.
• Dynamic effect of surface tension on liquid solidification molecular ionization for hypersonic flow.
• Numerical study on the diffusion of off-shore drilling mud.
• Wind tunnel test of turbulence intensity effect on the wake flow behind two cylinders in side arrangement.
• Light scattering experiments on high molecular weight polymer in binary liquid mixture.
• Numerical simulations and preliminary experiments on electrochemical deposition.

RESEARCH STAFF

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