Basic Science

New Achievements in Unimolecule Spin State Quantum Control

Recently, new headway was achieved on unimolecule spin-state quantum control by a research team under the leadership of Gao Hongjun at Nanoscale Physics and Devices Laboratory, the Institute of Physics, CAS in cooperation with Prof. Xie Xincheng and Prof. Werner A. Hofer from the University of Liverpool. The researchers found that in the Kondo effect of phthalocyanine iron molecules, the different adsorption positions of iron atoms in the molecule center on the metal surface have tremendous impact upon Kondo Effect. This finding was published by the Sep. 9 issue of Physical Review Letters (Phys. Rev. Lett. 99, 106402 (2007)). This is the first report revealing that the adsorption positions have the control power upon the unimolecule Kondo Effect, providing new thoughts for the research of unimolecule spin-state quantum control and its application in quantum information.

Photodynamics Controlled Nano-device Successfully Developed

Recently, the Shanghai Institute of Ceramics, CAS successfully built the Nanoscale device controlled by the molecule photodynamic effect, which is expected to be applied in fields of medical diagnosis, medication transportation as well as chemical process control and inspection, etc. This research was conducted by Prof. Zhu Yingchuan of the Shanghai Institute of Ceramics, in cooperation with Dr. Fujiwara Masahiro from AIST Research Institute of Japan. The result was published by the magazineAngewandte Chemie International Edition as a hot paper (Angew. Chem. Int. Ed, 2007, 46, 2241－2244, with impact factor being 10.232 for 2006). Patent application for this result has been submitted. Research shows that the functional molecules can be combined with nanoscale structure to realize multiple functions of nanoscale device. With the mechanism of photochemical reaction, all parts of nanoscale device can be controlled under the UV light-visible light to complete specific functions.

Major Research Results Published by Science

The Aug. 24 issue of Science published the latest discoveries of the research team on 1102 topic at State Key Laboratory of Molecular Reaction Dynamics, the Dalian Institute of Chemical Physics, CAS (317, 5841, 1061-1064). The team under the leadership of Yang Xueming and Zhang Donghui observed the F* + D2 reaction through the self-made advanced hydrogen atom Rydberg state time of flight spectrometry–crossed molecular beam instrument (exclusive in China), and surprisingly found the reaction of fluorine atoms at the excited state under low impact energy was much active than the fluorine at the ground state, which suggests that the image of Born-Oppenheimer approximation is not applicable to F+D2 reaction.? Moreover, the team on this topic joined hands with Prof. Sheng Liusi from National Synchrotron Radiation Laboratory, University of Science and Technology of China, in carrying out precise measurement of this percentage with VUV Synchrotron radiation light direct ionization method.? Prof. Alexander from University of Maryland and other cooperators carried out dynamic analysis upon full quantum scattering through precise potential energy surfaces of multiple couplings and brought forward the important and precise physical map depicting the nanodiabatic dynamics process.

New Progress Achieved on Nanotubes

New progress has been recently achieved on controlled synthesis of carbon nanotubes (CNTs) by researchers of the Key Laboratory of Organic Solids, the Institute of Chemistry, CAS. The application for Chinese invention patent was submitted and relevant research results were published by the latest issue of Journal of the American Chemical Society. (J. Am. Chem. Soc., 2007, 129(23), 7364－7368).

The research team ever invented the air fluctuation chemical vapor deposition process, namely, a method to produce the array of branched carbon nanotubes and to control their chemical components of all parts through changing the amount of airflow or its components (Nano Lett., 2006, 6, 186). Later, with different substrates, they realized the controlled synthesis of iron-encapsulated carbon nanotubes (Adv. Mater., 2007, 19, 386). Based on these achievements, they inserted an extra magnetic field during the process of producing carbon nanotubes with the traditional chemical vapor deposition method and successfully produced branched and encapsulated carbon nanotubes.

According to the finding, they put forward the new mechanism of producing branched and encapsulated carbon nanotubes. Namely, with the magnetic effect in the vertical direction, the catalyst particles coalesced and developed into the branched carbon nanotubes and with the magnetic effect in the horizontal direction, the catalyst particles decomposed and developed into encapsulated carbon nanotubes. This finding is helpful to enhance people’s understanding on the chemical vapor deposition process under magnetic effect and offers an effective means to produce branched and encapsulated carbon nanotubes, providing material foundation for nano circuit research.