Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Exotic particles, chilled and trapped, form giant matter wave: Excitons form Bose-Einstein condensate

As excitons cool to a fraction of a degree above absolute zero, they condense at the bottom of an electrostatic trap and spontaneously form coherent matter waves. Creating indirect excitons, with electrons and holes in separate layers of a semiconductor, allowed them to persist long enough to cool into this state.

Credit: Butov group/UCSD
As excitons cool to a fraction of a degree above absolute zero, they condense at the bottom of an electrostatic trap and spontaneously form coherent matter waves. Creating indirect excitons, with electrons and holes in separate layers of a semiconductor, allowed them to persist long enough to cool into this state.

Credit: Butov group/UCSD

Abstract:
Physicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave.

Exotic particles, chilled and trapped, form giant matter wave: Excitons form Bose-Einstein condensate

San Diego, CA | Posted on May 24th, 2012

This feat will allow scientists to better study the physical properties of excitons, which exist only fleetingly yet offer promising applications as diverse as efficient harvesting of solar energy and ultrafast computing.

"The realization of the exciton condensate in a trap opens the opportunity to study this interesting state. Traps allow control of the condensate, providing a new way to study fundamental properties of light and matter," said Leonid Butov, professor of physics at the University of California, San Diego. A paper reporting his team's success was recently published in the scientific journal Nano Letters.

Excitons are composite particles made up of an electron and a "hole" left by a missing electron in a semiconductor. Created by light, these coupled pairs exist in nature. The formation and dynamics of excitons play a critical role in photosynthesis, for example.

Like other matter, excitons have a dual nature of both particle and wave, in a quantum mechanical view. The waves are usually unsynchronized, but when particles are cooled enough to condense, their waves synchronize and combine to form a giant matter wave, a state that others have observed for atoms.

Scientists can easily create excitons by shining light on a semiconductor, but in order for the excitons to condense they must be chilled before they recombine.

The key to the team's success was to separate the electrons far enough from their holes so that excitons could last long enough for the scientists to cool them into a condensate. They accomplished this by creating structures called "coupled quantum wells" that separate electrons from holes in different layers of alloys made of gallium, arsenic and aluminum.

Then they set an electrostatic trap made by a diamond-shaped electrode and chilled their special semiconducting material in an optical dilution refrigerator to as cold as 50 milli-Kelvin, just a fraction of a degree above absolute zero.

A laser focused on the surface of the material created excitons, which began to accumulate at the bottom of the trap as they cooled. Below 1 Kelvin, the entire cloud of excitons cohered to form a single matter wave, a signature of a state called a Bose-Einstein condensate.

Other scientists have seen whole atoms do this when confined in a trap and cooled, but this is the first time that scientists have seen subatomic particles form coherent matter waves in a trap.

Varying the size and depth of the trap will alter the coherent exciton state, providing this team, and others, the opportunity to study the properties of light and mater in a new way.

This most recent discovery stems from an ongoing collaboration between Leonid Butov's research group in UC San Diego's Division of Physical Sciences, including Alexander High, Jason Leonard and Mikas Remeika, and Micah Hanson and Arthur Gossard in UC Santa Barbara's Materials Department. The Army Research Office and the National Science Foundation funded the experiments, and the Department of Energy supported the development of spectroscopy in the optical dilution refrigerator, the technique used to observe the exciton condensate in a trap.

####

For more information, please click here

Contacts:
Susan Brown

858-246-0161

Copyright © University of California - San Diego

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 News Press

News and information

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

Australian startup creates world’s first 100% cotton hydrophobic T-Shirts November 26th, 2014

The mysterious 'action at a distance' between liquid containers November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Physics

The mysterious 'action at a distance' between liquid containers November 26th, 2014

Imaging

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

A*STAR SIMTech wins international award for breaking new ground in actuators: SIMTech invention can be used in an array of industries, and is critical for next generation ultra-precision systems November 24th, 2014

Professional AFM Images with a Three Step Click SmartScan by Park Systems Revolutionizes Atomic Force Microscopy by Automatizing the Imaging Process November 24th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Chip Technology

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Nanometrics Announces Upcoming Investor Events November 19th, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Quantum Computing

Pseudospin-driven spin relaxation mechanism in graphene November 11th, 2014

Heat Transfer Sets the Noise Floor for Ultrasensitive Electronics November 11th, 2014

Noise in a microwave amplifier is limited by quantum particles of heat November 10th, 2014

Sussex physicists find simple solution for quantum technology challenge October 28th, 2014

Discoveries

The mysterious 'action at a distance' between liquid containers November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Announcements

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

Australian startup creates world’s first 100% cotton hydrophobic T-Shirts November 26th, 2014

The mysterious 'action at a distance' between liquid containers November 26th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Tools

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

JPK reports on the use of AFM and the CellHesion module to study plant cells at the University of Queensland November 25th, 2014

A*STAR SIMTech wins international award for breaking new ground in actuators: SIMTech invention can be used in an array of industries, and is critical for next generation ultra-precision systems November 24th, 2014

Professional AFM Images with a Three Step Click SmartScan by Park Systems Revolutionizes Atomic Force Microscopy by Automatizing the Imaging Process November 24th, 2014

Military

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Two sensors in one: Nanoparticles that enable both MRI and fluorescent imaging could monitor cancer, other diseases November 18th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

Energy

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Blu-ray disc can be used to improve solar cell performance: Data storage pattern transferred to solar cell increases light absorption November 25th, 2014

UO-industry collaboration points to improved nanomaterials: University of Oregon microscope puts spotlight on the surface structure of quantum dots for designing new solar devices November 20th, 2014

Research partnerships

SEMATECH to Showcase Innovation and Advances in Manufacturing at SEMICON Japan 2014: SEMATECH experts will share the latest techniques, emerging trends and best practices in advanced manufacturing strategies and methodologies November 26th, 2014

The mysterious 'action at a distance' between liquid containers November 26th, 2014

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Solar/Photovoltaic

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Blu-ray disc can be used to improve solar cell performance: Data storage pattern transferred to solar cell increases light absorption November 25th, 2014

UO-industry collaboration points to improved nanomaterials: University of Oregon microscope puts spotlight on the surface structure of quantum dots for designing new solar devices November 20th, 2014

Eight19 secures £1m funding: Investment to develop production technology, and expand commercial activities for organic photovoltaics November 19th, 2014

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More












ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE