Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

Keysight Technologies Shifts to Direct Sales of High-Performance Products in North America March 3rd, 2015

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Physics

Breakthrough in OLED technology March 2nd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Imaging

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Govt.-Legislation/Regulation/Funding/Policy

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

New nanodevice defeats drug resistance: Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs March 2nd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Chip Technology

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Quantum Computing

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Waterloo invention advances quantum computing research: New device, which will be used in labs around the world to develop quantum technologies, produces fragile entangled photons in a more efficient way February 16th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

Discoveries

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Announcements

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Democratizing synthetic biology: New method makes research cheaper, faster, and more accessible March 3rd, 2015

Pens filled with high-tech inks for do-it-yourself sensors March 3rd, 2015

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Tools

Keysight Technologies Shifts to Direct Sales of High-Performance Products in North America March 3rd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Military

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Simulating superconducting materials with ultracold atoms: Rice physicists build superconductor analog, observe antiferromagnetic order February 23rd, 2015

New nanogel for drug delivery: Self-healing gel can be injected into the body and act as a long-term drug depot February 19th, 2015

Energy

UC research partnership explores how to best harness solar power March 2nd, 2015

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Magnetic nanoparticles enhance performance of solar cells X-ray study points the way to higher energy yields February 25th, 2015

Research partnerships

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

The taming of magnetic vortices: Unified theory for skyrmion-materials March 3rd, 2015

Breakthrough in OLED technology March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Solar/Photovoltaic

UC research partnership explores how to best harness solar power March 2nd, 2015

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Magnetic nanoparticles enhance performance of solar cells X-ray study points the way to higher energy yields February 25th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE