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Two PKU achievements listed the top 10 scientific developments of China’s Universities for 2016

JAN . 09 2017
Peking University, Dec.28, 2016: On Dec.29, 2016, Commission for Science and Technology of Ministry of Education of China listed the top 10 scientific developments of China’s Universities for 2016 and two of them are from Peking University. One is ‘the First Stable Single-Molecule Junctions in the World’ led by Professor Guo Xuefeng from College of Chemistry and Molecular Engineering , and the other is ‘Nucleus Chiral Symmetry and Reflection Symmetry Spontaneously Breakings with Correlations’ led by Professor Meng Jie from School of Physics .

The First Stable Single-MoleculeJunctions in the World
 
Switches are common components of almost any electronic device and minimizing of switch to nano-scale is in demand due to the rapid development of nanoscience, while there are no established rules to fabricate electronic switches in molecular scale, so finding rules to assembling molecular to electronic switches is a meaningful focus.
 
Professor Guo’s group has been carrying out the research on molecular switches for 9 years. They fabricated a reversible molecular electrical switch consisting of a single diarylethene molecule in a junction comprising graphene electrodes.  Aiming to modulate the molecule-electrode coupling strengths, molecular engineering is the key to their success in constructing their reversible and stable electrical switches. This research means China has fabricated the first stable and reversible single-molecule electrical switch in the world.
 
This research was reported in the scientific journal Science (Science, 2016, 352,1443), and has applied for patents for inventions. Science made a positive comment in a perspective article at the same issue and stated that this work ‘represents exquisite control over matter atnanometer length scales and is a worthy intellectual pursuit in its own right with broad, long-term benefits’.( Science 2016, 352, 1394)
 
Nucleus Chiral Symmetry and Reflection Symmetry Spontaneously Breaking with Correlations

Spontaneous symmetry breaking is a fundamental concept in nature. Chiral symmetry (in short chirality) is very common in nature, such as architecture, left and right hands, trumpet shell, and they represent the beauty of chiral symmetry. Professor Meng and his cooperator predicted chiral symmetry breaking in atomic nuclei and has attracted considerable attention and intensive discussion since then. The chirality of nuclei can give information for the shape and motor pattern of it.

Professor Meng’s group has worked in the field of nuclear structure physics since 1980s and made great process: in 2006, he and his cooperators predicted multiple chiral doublet bands in nucleus, which attracted relating research; in 2011, they found chiral doublet bands existed in 80Br; in 2016, they identified two pairs of positive- and negative-parity doublet bands together with eight strong electric dipole transitions linking their positive- and negative-parity bands, which gave evidence for nucleus chiral symmetry and reflection symmetry breakings with correlations.

The research was reported in the scientific journal Physical Review Letters and selected as the cover article (Phys. Rev. Lett. 116, 112501). This is the first cover article of Chinese scholars in nuclear physics. This work finds evidence for octupole correlations in multiple chiral doublet bands and gives more information for the structure of nucleus.

‘Top 10 Scientific Developments of China’s University’ is announced by Commission for Science and Technology of Ministry of Education of China and has been held annually since 1998. 27 achievements from Peking University have been listed  since then, which tops the Chinese universities.

Written by: Li Yao
Edited by: Zhang Jiang