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Volume 2 Issue 12
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Original Articles
PHOTOLUMINESCENCE STUDIES OF GaAs-GaAlAs MULTIPLE QUANTUM WELLS
XU Zhong-ying, XU Ji-zong, CHEN Zong-gui, ZHUANG Wei-hua, XU Jun-ying, ZHENG Bao-zhen, TENG Da, LI Yu-zhang
Chin. Phys. Lett. 1985, 2 (12): 529-532 .  
Abstract   PDF(pc) (51KB) ( 501 )
Photoluminescence experiments have been performed on GaAg-GaAlAs. quantum well structures with well widths ranging from 40Å to 145Å. Both the intrinsic and extrinsic transitions have been observed. Relatively strong interface-related luminescence is believed to be due to the presence of more trapped impurities at the interfaces.

DANGLING-BOND AND VOID-LIKE STRUCTURE IN AMORPHOURS SEMICONDUCTORS
WU Xiang, CHEN Hong
Chin. Phys. Lett. 1985, 2 (12): 533-536 .  
Abstract   PDF(pc) (42KB) ( 428 )
To explain the differences in properties between the chalcogenide glassy semiconductors and the tetrahedrally-bonded semiconductors, a microscopic structural model is given in this letter. Based on this model, we can not only get two-level systems, negative-U pairs, and the Urbach rule, but also account for some recent experiments.
SELF-CONSISTENT ELECTRONIC STRUCTURE OF AuGa2
XU Jian-hua
Chin. Phys. Lett. 1985, 2 (12): 537-540 .  
Abstract   PDF(pc) (0KB) ( 167 )
Semi-relativistic self-consistent electronic structure of AuGa2 has been studied by means of linear muffin-tin orbitals method. The speculation of Switendick and Narath for the unusual Ga Knight shift in AuGa2, and the s-d compensation mechanism occurring in the gold alloys given by Watson have been confirmed.
CAN SINGLE-NUCLEON-MECHANISM GIVE CORRECT ASYMMETRY OF THE ( p, π+) REACTXON?
JIANG Ming-fang, ZHANG Zong-ye, YU You-wen, WU Shi-shu*
Chin. Phys. Lett. 1985, 2 (12): 541-544 .  
Abstract   PDF(pc) (40KB) ( 462 )
A comparatively detailed nonrelativistic investigation of the (p, π+) reaction has been made using Single-Nucleon-Mechanism. The results show that if eikonal distortion is a good approximation to high and medium energy scattering, SNM is inadequate to describe the reaction in producing asymmetry.

IONIZATION CHANNELS OF SUPEREXCITED MOLECULES
LIANG Xiao-ling, PAN Xiao-chuan, LI Jig-ming (C.M.Lee)
Chin. Phys. Lett. 1985, 2 (12): 545-548 .  
Abstract   PDF(pc) (47KB) ( 453 )
Infinite perturbed Rydberg states for molecules can be correlated with quantum defect parameters. We present our theoretical results of Rydberg series (ionization channels) for the NO molecules. In the fσ channel, there exists a resonance which leads to the fine structure near the X-ray absorption K edges. The resonance energy decreases as the internuclear distance increases. Such relation can be utilized to diagnose the relevant bond-length of the molecules chemisorbed on the surface.
MAGNETIC STRUCTURE AND TRANSITION OF AMORPHOUS Ndx Ni1-x THIN FILMS
DAI Dao-sheng, WAN Hong, LAN Jian, FANG Rei-yi, JI Yu-ping
Chin. Phys. Lett. 1985, 2 (12): 549-552 .  
Abstract   PDF(pc) (49KB) ( 399 )
The magnetic of Ndx Ni1-x, amorphous thin films were studied. It was found that the effective magnetic moment of Ni atom (μNi) approached to zero at X 0.26, and when X < 0.26 the composition dependence of μμNi followed approximately μNi = (0. 6-3X1.2) μB It is found that the aspermagnetic and speromagnetic structures coexist in the amorphous Nd-Ni films with X < 0.26, and only speromagnetic structure exists for X < 0.26.

PHASE DIAGRAM OF THE FERROMAGNETIC KONDO LATTICE
LI Zheng-zhong, QIU Yang
Chin. Phys. Lett. 1985, 2 (12): 553-556 .  
Abstract   PDF(pc) (45KB) ( 390 )
The ground state properties of the ferromagnetic (FM) Kondo lattice system are discussed by using the self-consistent field approximation. A phase diagram of the system including saturated ferromagnetic and FM-Kondo coexistent phases has been given. The results obtained can be used to explain the experimental observations for the first FM. Kondo lattice material Ce-Siξ.
MICROWAVE TRANSITION BETWEEN "CLOCK LEVELS" OF Cs BEAM PUMPED BY A GaAlAs DIODE LASER
SHANG Song-quan, WU Xin-xin, YAO Shu-tong, XIE Lin-zhen, WANG Yi-qiu
Chin. Phys. Lett. 1985, 2 (12): 557-560 .  
Abstract   PDF(pc) (49KB) ( 394 )
The microwave transition between two ground hyperfine sublevels of Cs atom has been observed by opticl pumping and optical detecting. The maximum population difference between "0-0" sublevels in single laser pumping case is achieved. The "Ramsey pattern" of "0-0" clock Level transition and "Rabi" transition structures are obtained, and their main characters agree with the theoretical results. A better Cs beam atomic clock performance would be expected when the inject microwave frequency is locked into the center of the "0-0" cLock Level transition" In this experimental setup.

THE LOCALIZED VIBRATIONAL MODES OF SOLITON IN TRANS- (CH)x
WU Chang-qin, SUN Xin, FU Rou-li*
Chin. Phys. Lett. 1985, 2 (12): 561-564 .  
Abstract   PDF(pc) (45KB) ( 416 )
Starting from SSH model of trans-(CH)x with finite length, all the localized vibrational modes of soliton have been figured out and the total number is found to be five. The first three coincide with those obtained in TLM model. Another two are new findings, the fourth is odd mode with three nodes and the fifth is a staggered mode with even parity.
THE FRACTIONAL FERMION NUMBER AND FRACTIONAL CHARGE INDUCED BY MAGNETIC MONOPOLE
WANG Rong-tai, NI Guanq-jiong
Chin. Phys. Lett. 1985, 2 (12): 565-568 .  
Abstract   PDF(pc) (41KB) ( 352 )
Based on the Levinson theorem and using the method of Green's function, we derive the general expressions of fractional charge and fractional fermion number induced by the background field of t'Hooft-Polyakov magnetic monopole.

STRUCTURAL CHANGES OF RECOVERY PROCESS IN AMORPHOUS ALLOYS STUDIED BY POSITRON ANNIHILATION
WANG Shao-jie, XU Yin-hua, TANG Zhong-xun and TIAN De-cheng
Chin. Phys. Lett. 1985, 2 (12): 569-572 .  
Abstract   PDF(pc) (46KB) ( 361 )
Positron lifetime measurements are applied to two amorphous alloys. In amorphous phase, annihilations from two kinds of positron traps are suggested. The positron lifetime is sensitive to structural relaxation and indicates pre-crystallization, and significantly decreases during crys-tallization. The observed positron responses to structural changes are well understood with quasi-crystalline model.

11 articles