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Observations of abundant structural and electronic phases in potassium-doped single-layer p-quaterphenyl film

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Science China(Physics,Mechanics & Astronomy) 2021年第5期64卷 54-62页

作者： Wei Chen MingQiang Ren Tong Zhang YaJun Yan DongLai Feng 2 3 Slate Key Laboratory of Surface PhysicsDepartmen1 of PhysicsFudan UniversityShanghai 200433China Hefei National Laboratory for Physical Sciences at the Microscale Department of PhysicsUniversity of Science and Technologv of ChinaHefei 230026China Collaborative Innovation Cener of Advanced Micosructures Nanjing 210093China

Scanning tunneling microscopy/spectroscopy is applied herein to study the pristine and potassium(K)-doped single-layer pquaterphenyl(P4P) films grown on the Au(111) substrate at the molecular level. Abundant complex structural and electronic phases are induced by various K doping. The Fermi-level pinning effect is observed at a low doping level. On the contrary,K3P4P exhibits intriguing versatile phases and properties because charge carriers are effectively doped in. For example, two kinds of molecular vibration modes with energies below 100 meV are observed, indicating a possible strong electron-phonon coupling. The splitting of the lowest unoccupied molecular orbital state in K3P4P illustrates an electronic correlation effect, and its strength varies for four different K3P4P phases with different structures. In addition, the appearance of a Kondo resonance on the molecular vacancy/impurity implies a local molecular magnetic moment. Our results demonstrate that the complex electronic properties of an alkali metal-doped P4P/Au film stem from the existence of many competing interactions, such as electronelectron correlations and electron-vibration coupling, which can be effectively tuned via variable carrier doping and molecular structure. Our work also opens new routes toward engineering novel molecular devices and creating new electronic phases in strongly correlated molecular materials.

关键词： scanning tunneling microscopy phenyl-based molecular film electronic correlation electron-vibration coupling Kondo effect

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Asthenosphere dynamics based on the H2O dependence of element diffusivity in olivine

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National Science Review 2021年第4期8卷 9-11页

作者： Tomoo Katsura Hongzhan Fei Bayerisches Geoinstitut University of Bayreuth Center for High Pressure Science and Technology Advanced Research

The oceanic asthenosphere is one of the most enigmatic regions in the Earth’s interior. The presence of seismic lowvelocity zones implies high softness at the top of the asthenosphere, which may cause smooth plate mo... 详细信息

关键词： scanning tunneling microscopy phenyl-based molecular film electronic correlation electron-vibration coupling Kondo effect

De novo domestication towards new crops

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National Science Review 2021年第4期8卷 40-41页

作者： Xianrong Xie Yao-Guang Liu State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources South China Agricultural University Guangdong Laboratory for Lingnan Modern Agriculture College of Life Sciences South China Agricultural University

Long-term natural and human selections have domesticated crops from their wild progenitors for millennia, leading to the fixation of a large number of agronomically beneficial alleles and traits in cultivated crops. However, this process has been extremely time-consuming, accompanied with negative consequences, such as genetic erosion,

关键词： scanning tunneling microscopy phenyl-based molecular film electronic correlation electron-vibration coupling Kondo effect

Coherent vibrational Dynamics of[Au_(25)(SR)_(18)]^(-) Nanoclusters

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Chinese Journal of Chemical Physics 2021年第5期34卷 598-604,I0003页

作者： Jie Kong Yan-zhen Wu Meng Zhou Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Coherent vibrational dynamics can be observed in atomically precise gold nanoclusters using femtosecond time-resolved pump-probe *** can not only reveal the coupling between electrons and vibrations,but also reflect the mechanical and electronic properties of metal nanoclusters,which holds potential applications in biological sensing and mass ***,we investigated the coherent vibrational dynamics of[Au_(25)(SR)_(18)]^(-)nanoclusters by ultrafast spectroscopy and revealed the origins of thesecoherent vibrations by analyzing their frequency,phase and probe wavelength *** coherent oscillations with frequency of 40 cm^(-1) and 80 cm^(-1) can be reproduced in the excited state dynamics of[Au_(25)(SR)_(18)]^(-),which should originate from acoustic vibrations of the Au13 metal *** analysis on the oscillations indicates that the 80 cm^(-1) mode should arise from the frequency modulation of the electronic states while the 40 cm^(-1) mode should originate from the amplitude modulation of the dynamic ***,it is found that the vibration frequencies of[Au_(25)(SR)_(18)]^(-)obtained in pump-probe measurements are independent of the surface ligands so that they are intrinsic properties of the metal *** results are of great value to understand the electron-vibration coupling of metal nanoclusters.

关键词： Atomically precise gold nanoclusters electron-vibration coupling Acoustic vibration Femtosecond transient absorption

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