Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Detecting the birth and death of a phonon

Abstract:
Phonons are discrete units of vibrational energy predicted by quantum mechanics that correspond to collective oscillations of atoms inside a molecule or a crystal. When such vibrations are produced by light interacting with a material, the vibrational energy can be transferred back and forth between individual phonons and individual packets of light energy, the photons. This process is called the Raman effect.

Detecting the birth and death of a phonon

Lausanne, Switzerland | Posted on June 7th, 2018

In a new study, the lab of Christophe Galland at EPFL's Institute of Physics has developed a technique for measuring, in real time and at room-temperature, the creation and destruction of individual phonons, opening up exciting possibilities in various fields such as spectroscopy and quantum technologies.

The technique uses ultra-short laser pulses, which are bursts of light that last less than 10-13 seconds (a fraction of a trillionth of a second). First, one such pulse is shot onto a diamond crystal to excite a single phonon inside it. When this happens, a partner photon is created at a new wavelength through the Raman effect and is observed with a specialized detector, heralding the success of the preparation step.

Second, to interrogate the crystal and probe the newly created phonon, the scientists fire another laser pulse into the diamond. Thanks to another detector, they now record photons that have reabsorbed the energy of the vibration. These photons are witnesses that the phonon was still alive, meaning that the crystal was still vibrating with exactly the same energy.

This is in strong contradiction with our intuition: we are used to seeing vibrating objects progressively lose their energy over time, like a guitar string whose sound fades away. But in quantum mechanics this is "all or nothing": the crystal either vibrates with a specific energy or it is in its resting state; there is no state allowed in between. The decay of the phonon over time is therefore observed as a decrease of the probability of finding it in the excited state instead of having jumped down to the rest state.

Through this approach, the scientists could reconstruct the birth and death of a single phonon by analyzing the output of the two photon detectors. "In the language of quantum mechanics, the act of measuring the system after the first pulse creates a well-defined quantum state of the phonon, which is probed by the second pulse," says Christophe Galland. "We can therefore map the phonon decay with very fine time resolution by changing the time delay between the pulses from zero to a few trillionths of a second (10-12 seconds or picoseconds)."

The new technique can be applied to many different types of materials, from bulk crystals down to single molecules. It can also be refined to create more exotic vibrational quantum states, such as entangled states where energy is "delocalized" over two vibrational modes. And all this can be performed in ambient conditions, highlighting that exotic quantum phenomena may occur in our daily life - we just need to watch very fast.

####

For more information, please click here

Contacts:
Nik Papageorgiou

41-216-932-105

Copyright © Ecole Polytechnique Fédérale de Lausanne

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

Reference

Related News Press

News and information

When Dirac meets frustrated magnetism August 3rd, 2020

New printing process advances 3D capabilities: Technology aims to improve quality of products used in business, industry and at home July 31st, 2020

TU Graz researchers synthesize nanoparticles tailored for special applications July 31st, 2020

Scientists discover new class of semiconducting entropy-stabilized materials July 31st, 2020

Quantum Physics

Atomtronic device could probe boundary between quantum, everyday worlds: Clouds of supercooled atoms offer highly sensitive rotation sensors and tests of quantum mechanics July 17th, 2020

Quantum simulation: Particle behavior near the event horizon of block hole July 16th, 2020

Science fiction becomes fact -- Teleportation helps to create live musical performance July 7th, 2020

Macroscopic quantum interference in an ultra-pure metal June 26th, 2020

Govt.-Legislation/Regulation/Funding/Policy

Physicists find misaligned carbon sheets yield unparalleled properties July 31st, 2020

Scientists discover new class of semiconducting entropy-stabilized materials July 31st, 2020

Nanoreactor strategy generates superior supported bimetallic catalysts July 31st, 2020

Study: Mapping crystal shapes could fast-track 2D materials: Experts call for global effort to clear hurdles to mass production July 27th, 2020

Possible Futures

Physicists find misaligned carbon sheets yield unparalleled properties July 31st, 2020

Way, shape and form: Synthesis conditions define the nanostructure of manganese dioxide July 31st, 2020

New printing process advances 3D capabilities: Technology aims to improve quality of products used in business, industry and at home July 31st, 2020

Scientists discover new class of semiconducting entropy-stabilized materials July 31st, 2020

Announcements

When Dirac meets frustrated magnetism August 3rd, 2020

New printing process advances 3D capabilities: Technology aims to improve quality of products used in business, industry and at home July 31st, 2020

TU Graz researchers synthesize nanoparticles tailored for special applications July 31st, 2020

Scientists discover new class of semiconducting entropy-stabilized materials July 31st, 2020

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

When Dirac meets frustrated magnetism August 3rd, 2020

Way, shape and form: Synthesis conditions define the nanostructure of manganese dioxide July 31st, 2020

New printing process advances 3D capabilities: Technology aims to improve quality of products used in business, industry and at home July 31st, 2020

TU Graz researchers synthesize nanoparticles tailored for special applications July 31st, 2020

Tools

Bruker Launches Revolutionary High-Speed AFM System for Single-Molecule Applications: JPK NanoRacer® Follows Molecular Dynamics in Real Time at 50 Frames per Second July 30th, 2020

Izon Science receives $10.5M investment from Bolton Equities: Christchurch-headquartered nanotech company secures investment to accelerate global growth; appoints top board chairman and directors July 28th, 2020

Study: Mapping crystal shapes could fast-track 2D materials: Experts call for global effort to clear hurdles to mass production July 27th, 2020

Project creates more powerful, versatile ultrafast laser pulse: Institute of Optics research sets record for shortest laser pulse for newly developed technology, work that has important applications in engineering and biomedicine July 24th, 2020

Photonics/Optics/Lasers

Scientists discover new class of semiconducting entropy-stabilized materials July 31st, 2020

Brazilian researchers develop an optical fiber made of gel derived from marine algae: Edible, biocompatible and biodegradable, these fibers have potential for various medical applications. The results are described in the journal Scientific Reports. July 24th, 2020

Manipulating non-magnetic atoms in a chromium halide enables tuning of magnetic properties: New approach creates synthetic layered magnets with unprecedented level of control over their magnetic properties July 24th, 2020

Photochromic bismuth complexes show great promise for optical memory elements July 24th, 2020

Dental

First measurement of electron energy distributions, could enable sustainable energy technologies June 5th, 2020

Gas storage method could help next-generation clean energy vehicles: Tremendous amounts of hydrogen and methane can be stored in nanoscopic pores April 17th, 2020

Novel nanoparticle-based approach detects and treats oral plaque without drugs August 17th, 2018

Dental plaque is no match for catalytic nanoparticles: Twice-daily rinses of FDA-approved nanoparticles broke apart oral biofilms and prevented tooth decay in a study led by Penn researchers August 8th, 2018

Quantum nanoscience

Macroscopic quantum interference in an ultra-pure metal June 26th, 2020

Process for 'two-faced' nanomaterials may aid energy, information tech June 26th, 2020

An EPiQS Pursuit: Physicist Andrea Young is chosen to receive an Experimental Investigator award from the Moore Foundation May 28th, 2020

Scientists break the link between a quantum material's spin and orbital states: The advance opens a path toward a new generation of logic and memory devices based on orbitronics that could be 10,000 times faster than today's May 15th, 2020

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