Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Transforming the Properties of Matter With Tunable Quantum Dots

Abstract:
System promises the possibility of designing artificial solids that can be switched through a variety of electronic phase transitions

It's a Semiconductor; Penn Researchers Transform the Properties of Matter With Tunable Quantum Dots

October 05, 2005

Researchers at the University of Pennsylvania may not have turned lead into gold as alchemists once sought to do, but they did turn lead and selenium nanocrystals into solids with remarkable physical properties. In the October 5 edition of Physical Review Letters, online now, physicists Hugo E. Romero and Marija Drndic describe how they developed am artificial solid that can be transformed from an insulator to a semiconductor.

The Penn physicists are among many modern researchers who have been experimenting with a different way of transforming matter through artificial solids, formed from closely packed nanoscale crystals, also called "quantum dots."

"Essentially, we're forming artificial solids from artificial atoms about 10 times larger than real atoms whose properties we can fine tune on the quantum level," said Drndic, an assistant professor in Penn's Department of Physics and Astronomy. "Artificial solids are expected to revolutionize the fabrication of electronic devices in the near future, but now we are only beginning to understand their fundamental behavior."

Artificial solids, in general, are constructed by specifically assembling a number of nanocrystals, each composed of only a few thousand atoms, into a closely packed and well-ordered lattice. Previous researchers have demonstrated that quantum dots can be manipulated to change their physical properties, particularly their optical properties. In fact, the blue laser, which will soon be put into use into commercial products, was a result of early research in changing the colors of quantum dots.

"Many of the physical parameters of these crystals, such as their composition, particle size and interparticle coupling, represent knobs that can be individually controlled at nanometer scales," Drndic said. "Variation of any of these parameters translates directly into either subtle or dramatic changes in the collective electronic, optical and magnetic response of the crystal. In this case we were able to adjust its electrical properties."

In their study, Drndic and her colleagues looked at the ability of artificial solids to transport electrons. They demonstrated that, by controlling the coupling of artificial atoms within the crystal, they could increase the electrical conductivity of the entire crystal.

According to the researchers, this system promises the possibility of designing artificial solids that can be switched through a variety of electronic phase transitions, with little influence from the local environment. Their findings represent a key step towards the fabrication of functional nanocrystal-based devices and circuits.

Quantum dots are more than simply analogous to individual atoms; they also demonstrate quantum effects, like atoms, but on a larger scale. As a tool for research, quantum dots make it possible for physicists to measure, firsthand, some things only described in theory.

"It is this versatility in both experiment and theory that can potentially turn these quantum dot solids into model systems for achieving a general understanding of the electronic structure of solids," Drndic said. "Not only are we making strides in creating a future generation of electronics, but in doing so we are also getting a deeper understanding of the fundamental properties of matter."

This research was funded through grants from the National Science Foundation and the Office of Naval Research.

####
Contact:
Greg Lester
215-573-6604
glester@pobox.upenn.edu



Copyright © University of Pennsylvania

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

Possible Futures

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Nanoelectronics

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Materials/Metamaterials

Fonon Announces 3D Metal Sintering Technology: Emerging Additive Nano Powder Manufacturing Technology August 28th, 2014

SouthWest NanoTechnologies CEO Dave Arthur to Discuss “Carbon Nanotubes and Automotive Applications” at The Automotive Composites Conference and Expo 2014 (ACCE2014) August 28th, 2014

Nanodiamonds Are Forever: A UCSB professor’s research examines 13,000-year-old nanodiamonds from multiple locations across three continents August 27th, 2014

Competition for Graphene: Berkeley Lab Researchers Demonstrate Ultrafast Charge Transfer in New Family of 2D Semiconductors August 26th, 2014

Announcements

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

Nanoscale assembly line August 29th, 2014

New analytical technology reveals 'nanomechanical' surface traits August 29th, 2014

New Vice President Takes Helm at CNSE CMOST: Catherine Gilbert To Lead CNSE Children’s Museum of Science and Technology Through Expansion And Relocation August 29th, 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