The unpaired spin S=1/2 states which occur at the ends of an S=1 Heisenberg-like antiferromagnetic chain,have been observed recently in low-temperature electron spin-resonance measurements of Ni(C_(2)H_(8)N_(2))_(2)NO...The unpaired spin S=1/2 states which occur at the ends of an S=1 Heisenberg-like antiferromagnetic chain,have been observed recently in low-temperature electron spin-resonance measurements of Ni(C_(2)H_(8)N_(2))_(2)NO_(2)ClO_(4) containing selected impurities.We present here a further study on this topic by far infrared transmission spectra under the magnetic field.The splitting of S=1/2 modes was clearly observed and explained by the interaction of S=1/2 modes at two nearby chains,which can be separated by vacancy-like defect.展开更多
We report the observation of photocurrent spectrum involving both the fundamental interband,extrinsic defect transitions β-FeSi_(2) and the intrinsic transitions of Si substrate and demonstrate the sensitivity and re...We report the observation of photocurrent spectrum involving both the fundamental interband,extrinsic defect transitions β-FeSi_(2) and the intrinsic transitions of Si substrate and demonstrate the sensitivity and reliability of the photocurrent measurement for revealing the energy band structure of β-FeSi_(2).The transition energies are in good agreement with the results of absorption measurement and the theoretical calculation based on a simple recombination model.展开更多
High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)...High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)and 7500cm^(2)/V.s(77K)have been obtained for heterostructures with x=0.3.The variation of hole mobility with temperature and the influence of Ge fraction on hole mobility were investigated.展开更多
Resonably good agreement among the photoluminescence,absorption,in-plane photocurrent and theoretical calculation demonstrates the effect of GaAs barrier width on the strain in In_(0.20)Ga_(0.80)As/GaAs single quantum...Resonably good agreement among the photoluminescence,absorption,in-plane photocurrent and theoretical calculation demonstrates the effect of GaAs barrier width on the strain in In_(0.20)Ga_(0.80)As/GaAs single quantum wells.The strain of each sample has been deduced.展开更多
Some fundamental properties are found for the singlet ground state and lowest triplet excited state in the spin s=1 linear chain Heisenberg antiferromagnet with arbitrary chain length.The influence of the anisotropic ...Some fundamental properties are found for the singlet ground state and lowest triplet excited state in the spin s=1 linear chain Heisenberg antiferromagnet with arbitrary chain length.The influence of the anisotropic term on these states is evaluated by spin polarization on the site of the chain.The energy levels based on these analyses are in good agreement with the experimental spectroscopes.展开更多
The polarization dependence of the Raman spectra of a single ultra-wide β-Ga2O3 nanobelt was studied.The spectra were found to strongly depend on the relative angle between the polarization of the incident light and ...The polarization dependence of the Raman spectra of a single ultra-wide β-Ga2O3 nanobelt was studied.The spectra were found to strongly depend on the relative angle between the polarization of the incident light and the axis of the β-Ga2O3 nanobelt.Such behavior was ascribed to the large length to width ratio of the nanostructure and its small dielectric constant.The ultra-wide β-Ga2O3 nanobelt was fabricated using catalyst-free thermal chemical vapor deposition.展开更多
We used the micro-Raman spectroscopy to investigate the V-grooved quantum well wires (QWWs), and first observed and assigned the Raman spectra of single QWW. They were the disorder induced modes at 223 and 243 cm-1, c...We used the micro-Raman spectroscopy to investigate the V-grooved quantum well wires (QWWs), and first observed and assigned the Raman spectra of single QWW. They were the disorder induced modes at 223 and 243 cm-1, confined LO mode of GaAs QWW at 267 cm-1, and higher order peaks of disorder induced modes at 488 and 707 cm-1.展开更多
基金Supported by the National Natural Science Foundation of ChinAlexander von Humboldt Foundation of F.R.Germanythe Foundation of Education Division of Chinese Academy of Sciences for Young Scientist.
文摘The unpaired spin S=1/2 states which occur at the ends of an S=1 Heisenberg-like antiferromagnetic chain,have been observed recently in low-temperature electron spin-resonance measurements of Ni(C_(2)H_(8)N_(2))_(2)NO_(2)ClO_(4) containing selected impurities.We present here a further study on this topic by far infrared transmission spectra under the magnetic field.The splitting of S=1/2 modes was clearly observed and explained by the interaction of S=1/2 modes at two nearby chains,which can be separated by vacancy-like defect.
文摘We report the observation of photocurrent spectrum involving both the fundamental interband,extrinsic defect transitions β-FeSi_(2) and the intrinsic transitions of Si substrate and demonstrate the sensitivity and reliability of the photocurrent measurement for revealing the energy band structure of β-FeSi_(2).The transition energies are in good agreement with the results of absorption measurement and the theoretical calculation based on a simple recombination model.
文摘High mobility Si/Si_(l-x)Ge_(x)/Si p-type modulation-doped double heterostructures have been grown by RRH/VLP-CVD(rapid radiant heating/very low pressure-CVD).Hole Hall mobilities as high as about 300cm^(2)/V.s(293 K)and 7500cm^(2)/V.s(77K)have been obtained for heterostructures with x=0.3.The variation of hole mobility with temperature and the influence of Ge fraction on hole mobility were investigated.
文摘Resonably good agreement among the photoluminescence,absorption,in-plane photocurrent and theoretical calculation demonstrates the effect of GaAs barrier width on the strain in In_(0.20)Ga_(0.80)As/GaAs single quantum wells.The strain of each sample has been deduced.
基金Alexander von Humboldt Foundation F.R.Germany,and the National Natural Science Foundation of China.
文摘Some fundamental properties are found for the singlet ground state and lowest triplet excited state in the spin s=1 linear chain Heisenberg antiferromagnet with arbitrary chain length.The influence of the anisotropic term on these states is evaluated by spin polarization on the site of the chain.The energy levels based on these analyses are in good agreement with the experimental spectroscopes.
基金supported by the National Natural Science Foundation of China and the National Basic Research Program of China (2011CB925602,2010DAF0260)
文摘The polarization dependence of the Raman spectra of a single ultra-wide β-Ga2O3 nanobelt was studied.The spectra were found to strongly depend on the relative angle between the polarization of the incident light and the axis of the β-Ga2O3 nanobelt.Such behavior was ascribed to the large length to width ratio of the nanostructure and its small dielectric constant.The ultra-wide β-Ga2O3 nanobelt was fabricated using catalyst-free thermal chemical vapor deposition.
文摘We used the micro-Raman spectroscopy to investigate the V-grooved quantum well wires (QWWs), and first observed and assigned the Raman spectra of single QWW. They were the disorder induced modes at 223 and 243 cm-1, confined LO mode of GaAs QWW at 267 cm-1, and higher order peaks of disorder induced modes at 488 and 707 cm-1.
