Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How photons change chemistry

16.03.2017

The quantum nature of light does usually not play an important role when considering the chemical properties of atoms or moelcules. In an article published in the Proceedings of the National Academy of Sciences scientists from the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron-Laser Science (CFEL) in Hamburg show, however, that under certain conditions photons can strongly influence chemistry. These results indicate the possibility that chemical processes can be tailored by photons.

The chemical properties of atoms and molecules are determined by the electromagnetic interaction between the negatively charged electrons and the positively charged nuclei. In most cases the quantum nature of the interaction does not play an important role.


Photons in an optical cavity alter the properties of molecules, such as their binding length.

Jörg M. Harms/MPSD

However, upon placing a molecule between two strongly reflecting mirrors, a so-called optical cavity, the quantum nature of the electromagnetic field can become important. In such a situation single photons can interact unusually strongly with the molecule, and one can no longer distinguish between molecule and photons. The properties of this new state of matter can be very different to the bare molecule, e.g., a higher conductivity.

Experimentally such situations have already been observed, but theoretical predictions of the chemical properties of such states were possible only to a limited extend. The reason being that the common quantum-chemical methods do not take into account the quantum nature of light.

The theory department of the Max Planck Institute for the Structure and Dynamics of Matter at CFEL has now extended some of these methods to include the coupling to the photons. Among other things, the group of Prof. Angel Rubio showed how strong coupling to photons in an optical cavity changes chemical properties of molecules, like its bond length or its absorption.

„Of special interest“, says Johannes Flick, the main author of the work, „are the changes of the Born-Oppenheimer surfaces, which are used to characterize chemical reactions. We found that strong light-matter coupling induces novel reaction pathways.“ At the same time the scientists investigated whether standard chemical reactions can be made more efficient by employing strong coupling to the photons. To do so, they considered a simple model of charge transfer between two quantum systems.

Such charge-transfer reactions are usually driven by a laser pulse. In this work, the reaction was assisted by a few photons in the optical cavity, which allowed for lower laser intensities. „Our theoretical findings do not only help to better understand the behavior of atoms and molecules strongly coupled to photons in an optical cavity,“ says Johannes Flick, „but they also highlight the possibility to change chemical properties via photons.“

In a next step the scientist want to apply their developed theoretical methods to more complex molecules. The goal is to show that the current results are generally valid and that one can alter the chemical properties of all sorts of different molecules via strong light-matter coupling.

Reference:
Atoms and Molecules in Cavities: From Weak to Strong Coupling in QED Chemistry.
Johannes Flick, Michael Ruggenthaler, Heiko Appel and Angel Rubio
PNAS, Early Edition - Doi: 10.1073/pnas.1615509114

Weitere Informationen:

http://www.mpsd.mpg.de/391004/20170315-flick-pnas-rubio - Institute news incl. contacts.
https://dx.doi.org/10.1073/pnas.1615509114 - Original publication site

Dr. Joerg Harms | Max-Planck-Institut für Struktur und Dynamik der Materie

More articles from Physics and Astronomy:

nachricht Unconventional superconductor may be used to create quantum computers of the future
19.02.2018 | Chalmers University of Technology

nachricht Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>