Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Creation of coherent states in molecules by incoherent electrons

Momentum images of H from H2 and D from D2 at different electron energies. The one at 4 eV for H is symmetric, while those above 14 eV are strongly asymmetric. The asymmetry in D is less pronounced and appear to change direction with change in electron energy.
CREDIT
E. Krishnakumar et al, Nature Physics
Momentum images of H from H2 and D from D2 at different electron energies. The one at 4 eV for H is symmetric, while those above 14 eV are strongly asymmetric. The asymmetry in D is less pronounced and appear to change direction with change in electron energy. CREDIT E. Krishnakumar et al, Nature Physics

Abstract:
In a breakthrough experiment using a novel negative ion momentum imaging technique, researchers from Tata Institute of Fundamental Research, Mumbai India and Open University, Milton Kyenes, UK have shown -- for the first time -- that incoherent electrons displaying their quantum mechanical nature, can induce coherence in molecular systems on attachment. Their latest results published in the Journal, Nature Physics (DOI: 10.1038/nphys4289), show that the coherence induced by the capture of single electron by H2 molecule results in the ejection of H? ion in preferentially backward direction with respect to the incoming electron beam. The other product of the dissociation is the H-atom in its excited state. In other words, this coherence induced in the molecule segregates the charge and excess energy in the system in a preferred manner. Similar measurements in the isotopomer of H2 namely D2 does not show such a strong asymmetry in ejection of the fragment ion but shows the reversal of the asymmetry as a function of incoming electron energy.

Creation of coherent states in molecules by incoherent electrons

Mumbai, India | Posted on October 21st, 2017

So far researchers have used such coherence induced by laser beams to control molecular dissociation and have considered it as the basis for possible control of chemical reactions using photons. But in that case, the coherence in the resulting excited molecular entity is understood to stem from the absorbed laser radiation. By demonstrating the presence of such coherence resulting from a capture of an incoherent electron, Prof. Krishnakumar and co-workers have shown that such coherence can also stem from the transfer of more than one value of angular momentum quanta.

On the capture of a low energy electron, a relatively unstable molecular negative ion is formed. Subsequently, this negative ion decays by ejecting the extra electron. However, if the ion survives against the electron ejection, it undergoes dissociation. This is known as dissociative attachment. According to Prof. Krishnakumar, dissociative attachment is traditionally linked with transfer of multiple values of angular momentum quanta in the molecular system. However, it is for the first time such a quantum coherent response has been observed from a molecule.

Low energy electrons are ubiquitous and are known to play important role in variety of phenomena relevant to astrochemistry (where they participate in synthesis of new molecules), in radiation biology (where they cause chemical changes in living cell, plasma chemistry), atmospheric chemistry, radioactive waste management and nanolithography -- to name but a few. In all these cases, dissociative attachment plays a critical role. The unstable excited molecular negative ion states are at the core of this process. However, due to very short lifetime of these species very little is known about them at present.

The group led by Prof. Krishnakumar and Dr. Prabhudesai in TIFR has pioneered research on several aspects of low energy electron interactions with molecules in gas and condensed phase with particular emphasis on the possibility of controlling chemical reactions using low energy electrons. These new results point to rich unexplored dynamics of excited molecular negative ions that might open up new possibilities in inducing chemical control. They also pose a challenge to theoreticians to come up with a detailed model for the negative ion chemistry that is associated with low energy free electron scattering.

These measurements were carried out by Prof. Krishnakumar using an experiment built by him at the Open University in UK, where he was on invitation as a Marie Curie Professor to help build a novel electron scattering experiment for the European scientists, similar to the one he had conceived and built at TIFR. Dr. Prabhudesai and Prof. Krishnakumar provided the interpretation of the data along with the model.

####

For more information, please click here

Contacts:
E. Krishnakumar

91-986-901-3407

Copyright © Tata Institute of Fundamental Research

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Iran Produces Cooling Fabrics Using Nanotechnology October 17th, 2018

Iran World’s Second Largest Producer of Nano-Catalysts October 17th, 2018

Iran Unveils Its First Homegrown 3D Nano Printer October 17th, 2018

Fat-Repellent Nanolayers Can Make Oven Cleaning Easier October 17th, 2018

Chemistry

Iran World’s Second Largest Producer of Nano-Catalysts October 17th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Light makes Rice U. catalyst more effective: Halas lab details plasmonic effect that allows catalyst to work at lower energy October 5th, 2018

Imaging

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Extracting energy from a 60 nanometers thin layer October 5th, 2018

Discoveries

Researchers quickly harvest 2-D materials, bringing them closer to commercialization: Efficient method for making single-atom-thick, wafer-scale materials opens up opportunities in flexible electronics October 12th, 2018

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Tracking a Killer: UCSB, UCSD and SBP researchers trace the complex and variable pathways to the deadly condition known as sepsis October 12th, 2018

Announcements

Arrowhead Pharmaceuticals Hosts R&D Day on Pipeline of RNAi Therapeutics October 17th, 2018

Iran Produces Cooling Fabrics Using Nanotechnology October 17th, 2018

Iran World’s Second Largest Producer of Nano-Catalysts October 17th, 2018

Iran Unveils Its First Homegrown 3D Nano Printer October 17th, 2018

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Tracking a Killer: UCSB, UCSD and SBP researchers trace the complex and variable pathways to the deadly condition known as sepsis October 12th, 2018

Tools

Iranian Firm Offering Nano-Products on Chinese Market October 16th, 2018

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Nanometrics to Announce Third Quarter Financial Results on October 30, 2018 October 10th, 2018

UCI scientists push microscopy to sub-molecular resolution: Carbon monoxide used to measure electric forces in single chemical compound October 2nd, 2018

Photonics/Optics/Lasers

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

Columbia Engineers Build Smallest Integrated Kerr Frequency Comb Generator October 9th, 2018

AIM Photonics is Unveiling Support for Datacom and Telecom Optical Bands with its New Silicon Photonics Process Design Kit (PDK): New Analog Photonics and SUNY PDK Enables Partnering Companies to Gain World-Class Technological Capabilities in O+C+L optical bands October 5th, 2018

Light makes Rice U. catalyst more effective: Halas lab details plasmonic effect that allows catalyst to work at lower energy October 5th, 2018

Printing/Lithography/Inkjet/Inks/Bio-printing

Iran Unveils Its First Homegrown 3D Nano Printer October 17th, 2018

Laser sintering optimized for printed electronics: New study sheds (laser) light on the best means of laying down thin-film circuitry September 13th, 2018

Virginia Tech researchers develop novel process to 3D print one of the strongest materials on Earth August 23rd, 2018

Color effects from transparent 3D printed nanostructures: New design tool automatically creates nanostructure 3D print templates for user-given colors Scientists present work at prestigious SIGGRAPH conference August 18th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project