Menu
Modern science
Soil Microbes Accelerate Global Warming

Bold New Approach to Wind 'Farm' Design May Provide Efficiency Gains

Soft Memory Device Opens Door to New Biocompatible Electronics

Most Elliptical Galaxies Are 'Like Spirals'

New Planets Feature Young Star and Twin Neptunes

Editing the Genome: Scientists Unveil New Tools for Rewriting the Code of Life

High Social Rank Comes at a Price, Wild Baboon Study Finds

Fossil Forensics Reveals How Wasps Populated Rotting Dinosaur Eggs

Monitoring Cellular Interactions at Nano-Scale in More Detail Than Ever Before

Non-Africans Are Part Neanderthal, Genetic Research Shows

Making Blood Sucking Deadly for Mosquitoes

Rising Oceans: Too Late to Turn the Tide?

Newly Developed Fluorescent Protein Makes Internal Organs Visible

NASA's Dawn Spacecraft Returns Close-Up Image of Giant Asteroid Vesta

Bacteria Use Batman-Like Grappling Hooks to 'Slingshot' On Surfaces, Study Shows

Mysterious Fossils Provide New Clues to Insect Evolution

Twisted Tale of Our Galaxy's Ring: Strange Kink in Milky Way

Engineering Excitable Cells for Studies of Bioelectricity and Cell Therapy

Ancient Footprints Show Human-Like Walking Began Nearly 4 Million Years Ago

Memories May Skew Visual Perception

Movement of Black Holes Powers Quasars, the Universe's Brightest Lights

First Artificial Neural Network Created out of DNA: Molecular Soup Exhibits Brainlike Behavior

Dolphins' 'Remarkable' Recovery from Injury Offers Important Insights for Human Healing

Cosmological Evolution of Dark Matter Is Similar to That of Visible Matter

Exoplanet Aurora: An Out-Of-This-World Sight

New Material Lets Electrons 'Dance' and Form New State
A team of Purdue University researchers is among a small group in the world that has successfully created ultrapure material that captures new states of matter and could have applications in high-speed quantum computing.

The material, gallium arsenide, is used to observe states in which electrons no longer obey the laws of single-particle physics, but instead are governed by their mutual interactions.

Michael Manfra, the William F. and Patty J. Miller Associate Professor of Physics who leads the group, said the work provides new insights into fundamental physics.

"These exotic states are beyond the standard models of solid-state physics and are at the frontier of what we understand and what we don't understand," said Manfra, who also is an associate professor of both materials engineering and electrical and computer engineering. "They don't exist in most standard materials, but only under special conditions in ultrapure gallium arsenide semiconductor crystals."

Quantum computing is based on using the quantum mechanical behavior of electrons to create a new way to store and process information that is faster, more powerful and more efficient than classical computing. It taps into the ability of these particles to be put into a correlated state in which a change applied to one particle is instantly reflected by the others. If these processes can be controlled, they could be used to create parallel processing to perform calculations that are impossible on classical computers.

"If we could harness this electron behavior in a semiconductor, it may be a viable approach to building a quantum computer," Manfra said. "Of course this work is just in its very early stages, and although it is very relevant to quantum computation, we are a long way off from that. Foremost at this point is the chance to glimpse unexplained physical phenomena and new particles."

Manfra and his research team designed and built equipment called a high-mobility gallium-arsenide molecular beam epitaxy system, or MBE, that is housed at Purdue's Birck Nanotechnology Center. The equipment makes ultrapure semiconductor materials with atomic-layer precision. The material is a perfectly aligned lattice of gallium and arsenic atoms that can capture electrons on a two-dimensional plane, eliminating their ability to move up and down and limiting their movement to front-to-back and side-to-side.

"We are basically capturing the electrons within microscopic wells and forcing them to interact only with each other," he said. "The material must be very pure to accomplish this. Any impurities that made their way in would cause the electrons to scatter and ruin the fragile correlated state."

The electrons also need to be cooled to extremely low temperatures and a magnetic field is applied to achieve the desired conditions to reach the correlated state.

Gabor Csathy, an assistant professor of physics, is able to cool the material and electrons to 5 millikelvin -- close to absolute zero or 460 degrees below zero Fahrenheit -- using special equipment in his lab.

"At room temperature, electrons are known to behave like billiard balls on a pool table, bouncing off of the sides and off of each other, and obey the laws of classical mechanics," Csathy said. "As the temperature is lowered, electrons calm down and become aware of the presence of neighboring electrons. A collective motion of the electrons is then possible, and this collective motion is described by the laws of quantum mechanics."

The electrons do a complex dance to try to find the best arrangement for them to achieve the minimum energy level and eventually form new patterns, or ground states, he said.

Csathy, who specializes in quantum transport in semiconductors, takes the difficult measurements of the electrons' movement. The standard metric of semiconductor quality is electron mobility measured in centimeters squared per volt-second. The group recently achieved an electron mobility measurement of 22 million centimeters squared per volt-second, which puts them among the top two to three groups in the world, he said.

Manfra and Csathy presented their work at Microsoft's Station Q summer meeting on June 17 at the University of California at Santa Barbara. This meeting, sponsored by Microsoft Research, brings together leading researchers to discuss novel approaches to quantum computing. They also received a $700,000 grant from the Department of Energy based on their preliminary results.

In addition to Manfra and Csathy, the research team includes associate professors of physics Leonid Rokhinson and Yuli Lyanda-Geller; professor of physics Gabriele Giuliani; graduate students John Watson, Nodar Samkharadze, Nianpei Deng and Sumit Mondal; and research engineer Geoff Gardner.

"A broad team is necessary to probe this type of physics," Manfra said. "It takes a high level of expertise in materials, measurement and theory that is not often found at one institution. It is the depth of talent at Purdue and ability to easily work with researchers in other areas that made these achievements possible."

Для печати

New Material Lets Electrons 'Dance' and Form New State

Cod Resurgence in Canadian Waters

Fundamental Matter-Antimatter Symmetry Confirmed

First True View of Global Erosion

NASA's WISE Finds Earth's First 'Trojan' Asteroid

Engineers Fly World's First 'Printed' Aircraft

Scientist Converts Human Skin Cells Into Functional Brain Cells

Rainforest Plant Developed 'Sonar Dish' to Attract Pollinating Bats

Sea Level Rise Less from Greenland, More from Antarctica, Than Expected During Last Interglacial

How Bats Stay On Target Despite the Clutter

Fall of the Neanderthals: Volume of Modern Humans Infiltrating Europe Cited as Critical Factor

Largest-Ever Map of Plant Protein Interactions

Some Plants Duplicate Their DNA to Overcome Adversity

access serial port from virtual machine

Menu
Diamonds Pinpoint Start of Colliding Continents

Researchers Identify Seventh and Eighth Bases of DNA

Fool's Gold Gives Scientists Priceless Insight Into Earth's Evolution

Astronomers Discover Largest and Most Distant Reservoir of Water Yet

Major Step Toward Creating Faster Electronics Using Graphene

New Photonic Crystals Have Both Electronic and Optical Properties

Epigenetic 'Memory' Key to Nature Versus Nurture

Climate Change to Increase Yellowstone Wildfires Dramatically

Retinal Cells Thoughts to Be the Same Are Not, Biologist Says

Minority Rules: Scientists Discover Tipping Point for the Spread of Ideas

Mitochondria Share an Ancestor With SAR11, a Globally Significant Marine Microbe

Drug Shown to Improve Sight for Patients With Inherited Blindness

Elliptical Galaxies Are Not Dead

Hubble Constant: A New Way to Measure the Expansion of the Universe

Enceladus Rains Water Onto Saturn

Engineers Develop One-Way Transmission System for Sound Waves

Researchers Graft Olfactory Receptors Onto Nanotubes

New Invisibility Cloak Hides Objects from Human View

Bionic Microrobot Mimics the 'Water Strider' and Walks On Water

How Memory Is Lost: Loss of Memory Due to Aging May Be Reversible

Reservoirs of Ancient Lava Shaped Earth

Wave Power Can Drive Sun's Intense Heat

Social Deficits Associated With Autism, Schizophrenia Induced in Mice With New Technology

Tundra Fires Could Accelerate Climate Warming

Chandra X-Ray Observatory Images Gas Flowing Toward Black Hole