There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

"...a blend of erudition (fascinating and sometimes obscure historical minutiae abound), popularization (mathematical rigor is relegated to appendices) and exposition (the reader need have little knowledge of the fields involved) ...and the illustrations include many superb examples of computer graphics that are works of art in their own right." Nature

The Fractal Geometry of Nature

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. It has moved into a central place in condensed matter studies. Statistical physics, and more specifically, the theory of transitions between states of matter, more or less defines what we know about 'everyday' matter and its transformations. The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable information on important recent developments.

Phase Transitions and Critical Phenomena

The electronic excitations from 0.1 to 2.5 eV in pure and lightly oxygen doped single-crystal La2CuO4+y are studied by means of polarization and temperature dependent reflectivity and transmission measurements. We discuss the current understanding of these excitations. In particular, we demonstrate that both extended and localized holes interact with optical phonon modes and form large polarons. Moreover, in undoped La2CuO4 we show the existence of weakly electric dipole allowed excitons with multimagnon sidebands.

Electronic Excitations in Undoped and Lightly Oxygen Doped La2CuO4+y

Neutron scattering experiments reveal that a diagonal spin modulation, which is a one-dimensional modulation rotated away by 45 from that in the superconducting phase, occurs universally across the insulating spin-glass phase in La2−xSrxCuO4 (0.02≤ x ≤0.055). This establishes an intimate relation between the magnetism and the transport properties in the high-temperature copper oxide superconductors. Furthermore, it is found that the charge density per unit length estimated using a charge stripe model is almost constant throughout the phase diagram, even when the modulation rotates away by 45 at the superconducting boundary. However, at the lowest values for x the density changes approaching 1 hole/Cu as in La2−xSrxNiO4. Magnetic excitation spectra suggest that magnetic correlations change from incommensurate to commensurate at ω ∼7 meV and T ∼70 K, indicating a characteristic energy for the incommensurate structure of 6-7 meV.

Ju n 20 00 Static and dynamic spin correlations in the spin-glass phase of slightly-doped

Static and Dynamic Spin Fluctuations in the Spin Glass Doping Regime in Lanthanum Strontium Copper Oxide (La2-xSrxCuO4+δ)

Random field effects in magnets

Y. J. Kim, R. J. Birgeneau, F. C. Chou, R. W. Erwin, and M. A. Kastner Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (March 21, 2022)

Robert J. Birgeneau

Papers

Electronic Excitations in Undoped and Lightly Oxygen Doped La2CuO4+y

Ju n 20 00 Static and dynamic spin correlations in the spin-glass phase of slightly-doped

Static and Dynamic Spin Fluctuations in the Spin Glass Doping Regime in Lanthanum Strontium Copper Oxide (La2-xSrxCuO4+δ)

Random field effects in magnets

Fe b 20 01 Critical spin dynamics of the 2 D quantum Heisenberg antiferromagnets : Sr 2 CuO