Chen Tengteng, who comes from Yancheng, Jiangsu Province, graduated from the Junior Class of the University of Science and Technology of China. He was also a student of the first "Yan Jici Physics Elite Class". During this period, he studied under academician Du Jiangfeng. Subsequently, he graduated with a Ph.D. from Brown University in the United States and is currently a postdoctoral fellow at University of California, San Diego.
Picture | Chen Tengteng (Source: Chen Tengteng)
Not long ago, his Science paper was officially published. During the research, he and his team explored the reaction process of molecular isomerization, which involved the Berry pseudo-rotation of compound pentacarbonyl iron , resulting in the energy transfer of two vibrational energy levels.
Berry pseudorotation, first proposed by American scientist Richard Stephen Berry, refers to a way in which the two axial ligands in the molecule exchange with the two horizontal ligands , thereby isomerizing the molecule.
In the molecular isomerization reaction studied by Chen Tengteng, only needs to cross one energy barrier and the reaction can occur in a solution at room temperature, which is representative in various chemical reaction systems.
Through such a representative system, he and his colleagues discovered that the energy transfer rate of polaritons is 30% higher than that of normal molecules. Moreover, compared with normal molecules, the different energy transmission paths of polaritons will undergo significant changes. In the research of
, they proved for the first time that the strong coupling of molecular vibrations to can change the ultrafast chemical reaction rate of molecules and speed up or slow down different energy transmission paths. This opens up new ideas for explaining the principle of strong coupling of molecular vibrations to change chemical reactions.
On the other hand, it also studied the dynamic properties of the dark energy level for the first time. It was found that most dark energy level dynamics are almost the same as those of normal solution molecules.
This is consistent with the theoretical prediction of Chen Tengteng and colleagues: that is, only the dynamic properties of the polarization unit have changed, and this discovery also points out a new research path to enhance the vibrational strong coupling effect of molecules.
At the same time, this achievement has 4 potential application values:
First, using the strong coupling effect of vibration, you only need to place the solution between two high reflectivity mirrors (the simplest optical cavity), without the need for costly complex catalysts or high temperature and pressure, to change the rate and output of chemical reactions.
Second, the use of vibrational polaritons can realize energy transmission within molecules, thus opening up a new situation for the synthesis of new compounds.
Third, using vibrational polaritons, quantum systems can be constructed at room temperature and are expected to be used in quantum computing , quantum information and other fields.
Fourth, by using vibrational polaritons, a single quantum system at room temperature can be achieved to achieve macroscopic quantum effects, thereby preparing new quantum materials.
(Source: Science)
Promote understanding of the chemical principles of polaritons
According to reports, strong coupling of vibrational dynamics can be achieved by simply placing a chemical solution in an optical cavity - this is a very interesting physical phenomenon.
In addition, only two mirrors with high reflectivity can form the simplest optical cavity. Mirrors are very reflective, so light bounces between the two mirrors and takes a long time to decay.
When a chemical solution is placed between two mirrors, light will interact with the chemical solution many times.When the attenuation rate of light in the cavity and the energy attenuation rate of the chemical solution are both lower than the interaction rate between light and solution, a non-local quasi-particle , which is a polariton, will be formed. That is, it is no longer a single light or solution molecule, but has the characteristics of both light and molecules.
At this time, through the strong coupling of the vibrational state, the interaction between light and matter can be enhanced, thereby changing the energy level arrangement of the system, and thus changing the nature of the chemical reaction.
Previously, Norwegian scientist Thomas Ebbesen and his collaborators discovered that through strong coupling of vibrations, chemical reaction rates and chemical outputs can be changed by simply placing a chemical solution between two highly reflective mirrors.
Based on this unexpected discovery, polariton chemical reactions quickly became a hot scientific research topic. At the same time, Thomas Ebbesen's experiments also aroused huge discussion because of their repeatability.
So how does strong vibrational coupling change chemical reactions? Regarding this issue, it was basically a “scientific research no man’s land” before. In particular, the dynamics that occupy most of the dark energy level have never been studied before. Chen Tengteng’s achievement fills the above gap.
Recently, a related paper titled "Cavity-enabled enhancement of ultrafast intramolecular vibrational redistribution over pseudorotation" was published on Science [1].
Figure | Related papers (Source: Science)
The first author and co-author are Chen Tengteng and Yang Zimo ( University of Science and Technology of China 2013 Department of Physics alumni), and Xiong Wei, professor of chemistry and biochemistry at the University of California, San Diego, serves as the corresponding author.
During the paper review process, they received the following evaluation: "This work established a standard system. The authors studied a textbook-style chemical system, which has broad application prospects and scientific significance. It is a very novel work and has groundbreaking significance."
Same period Science A perspective article was also published titled "Using mirrors to control molecular dynamics". The article also spoke highly of this achievement. said that this work proved that can use polaritons to change the molecular configuration that cannot be achieved by traditional chemical synthesis methods. also said that this research is an important step in understanding the chemical principles of polaritons.
(Source: Science)
crashed several times. At one time, I wanted to change the subject.
However, the process of publishing the paper was "a thousand twists and turns". Chen Tengteng said: "I learned basic experimental operations in the third month of my postdoc. 'Newborn calves are not afraid of tigers.' I told my supervisor that I wanted to be responsible for an independent work.
He said that he would try the pentacarbonyl iron system. Regarding the normal molecules of this system, other teams had studied it using two-dimensional infrared spectroscopy , and the paper was published in 2008 Science [2]. "
In September 2020, Chen Tengteng officially established the project. Initially, he and his colleagues successfully replicated the 2008 results. However, when the pentacarbonyl iron solution is put into the optical cavity, the complexity rises to a higher level, and it is impossible to even analyze the experimental data.
To this end, Chen Tengteng and his tutor often discussed until midnight and used various models to explain and analyze the data.
At first, they tried using conventional methods, but the results were not satisfactory. Subsequently, in order to understand the energy transfer between different energy levels, the research team created a dynamic model.
Using this model, they analyzed the ratio of different signals in the experimental spectrum. Later, in order to describe the system more accurately, each signal was fitted, thus verifying the correctness of the above model.
Later, a more stable and faster data collection method was adopted, which greatly improved the signal-to-noise ratio of the data and improved the stability and repeatability of the data.
Next, by controlling a series of variables in the experiment, they tried to find out the deeper mechanism of energy transfer.
It was found that with the anisotropy of the measured data, it is possible to clearly distinguish whether it is the false rotation of Berry molecules or the redistribution of vibrational energy within the molecule that leads to the transmission of energy. After the paper was submitted, this method was highly praised by the reviewers.
In fact, during this period, Chen Tengteng had the intention of quitting several times, and once wanted to change to a simpler subject. At that time, he had been working as a postdoc for two years, and he still had zero published papers, and he was very anxious. While studying for a Ph.D., I could produce a one-author paper about every five or six months.
"Comparing the two, I felt a huge psychological gap. Under this pressure, I wanted to give up several times when I collapsed." He said. The most recent "crash" of
before the paper went online occurred at the end of 2021. then. Chen Tengteng and his colleagues believe that the pentacarbonyl iron system has been basically understood, and the model can also roughly explain the proportion of different signals in the data.
He said: "I almost finished the first draft of the paper, but when I showed it to our theoretical collaborator Prof. Joel Yuen-Zhou's research group, the other party raised different opinions and believed that our model was missing some key factors."
For this reason, Chen Tengteng and his team had to overturn the old model and build a model from scratch after discussing with collaborators. He continued: "I originally thought that the paper would be published soon. However, I had to start from scratch. The publication time was far away, and I lost motivation."
At this time, my supervisor Professor Xiong Wei came to encourage me. He encouraged him: "Although the publication of the paper was delayed, it also ensured the solidity of the work. And with our previous experience, we should be able to solve it soon this time." Seeing his teacher's rigorous and optimistic academic style also made Chen Tengteng cheer up again, and finally achieved a perfect ending.
(Source: Science)
It is also reported that Chen Tengteng has also published a paper in the "Annual Review of Physical Chemistry" (Annual Review of Physical Chemistry) as a first author, and many other papers have been included in other top journals.
He said: "Annals of Physical Chemistry is the most authoritative review journal in the field of physical chemistry. It publishes less than 20 articles every year, and no more than ten people in China have published in this journal."
He also won the 2020 National Scholarship for Outstanding Self-funded International Students . At the same time, he is also actively using what he has learned to repay the motherland: he has carried out a series of cooperation with researchers from Tsinghua University, University of Science and Technology of China, Fudan University, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Shanxi University and other domestic universities.
The old work is still over, and new challenges are on the way. Currently, Chen Tengteng and his research group are exploring how to better control the efficiency and rate of energy transmission by adjusting different experimental factors such as temperature, solution concentration, and optical cavity parameters for the strong coupling of vibrational states. In addition, they also plan to study whether strong coupling of vibrational dynamics can change more chemical systems.
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