Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > The First Non-Trivial Atom Circuit: Progress towards an Atom SQUID Closer Look at Cell Membrane Shows Cholesterol 'Keeping Order' A Measurement First: NIST 'Noise Thermometry' System Measures Boltzmann Constant Microreactors: Small Scale Chemistry Could Lead to Big Improvements f

Atom circuit: False color images of an "atom circuit" made of an ultracold sodium gas. Red denotes a greater density of atoms and traces the path of circulating atoms around the ring. A laser-based barrier can stop the flow of atoms around the circuit (left); without the barrier the atoms circulate around the ring (right).
Credit: JQI/NIST
Atom circuit: False color images of an "atom circuit" made of an ultracold sodium gas. Red denotes a greater density of atoms and traces the path of circulating atoms around the ring. A laser-based barrier can stop the flow of atoms around the circuit (left); without the barrier the atoms circulate around the ring (right).
Credit: JQI/NIST

Abstract:
Researchers from the National Institute of Standards and Technology (NIST) and the University of Maryland (UM) have created the first nontrivial "atom circuit," a donut-shaped loop of ultracold gas atoms circulating in a current analogous to a ring of electrons in a superconducting wire. The circuit is "nontrivial" because it includes a circuit element—an adjustable barrier that controls the flow of atom current to specific allowed values. The newly published* work was done at the Joint Quantum Institute, a NIST/UM collaboration.

The First Non-Trivial Atom Circuit: Progress towards an Atom SQUID Closer Look at Cell Membrane Shows Cholesterol 'Keeping Order' A Measurement First: NIST 'Noise Thermometry' System Measures Boltzmann Constant Microreactors: Small Scale Chemistry Could Lead to Big Improvements f

Boulder, CO | Posted on March 31st, 2011

Ultracold gases, such as the Bose-Einstein condensate of sodium atoms in this experiment, are fluids that exhibit the unusual rules of the quantum world. Atomic quantum fluids show promise for constructing ultraprecise versions of sensors and other devices such as gyroscopes (which stabilize objects and aid in navigation). Super?uid helium circuits have already been used to detect rotation. Superconducting quantum interference devices (SQUIDs) use superconducting electrons in a loop to make highly sensitive measurements of magnetic fields. Researchers are striving to create an ultracold-gas version of a SQUID, which could detect rotation. Combined with ultracold atomic-gas analogs of other electronic devices and circuits, or "atomtronics" that have been envisioned, such as diodes and transistors, this work could set the stage for a new generation of ultracold-gas-based precision sensors.

To make their atom circuit, researchers created a long-lived persistent current—a frictionless flow of particles—in a Bose-Einstein condensate of sodium atoms held by an arrangement of lasers in a so-called optical trap that confines them to a toroidal, or donut, shape. Persistent flow—occurring for a record-high 40 seconds in this experiment—is a hallmark of superfluidity, the fluid analog of superconductivity.

The atom current does not circle the ring at just any velocity, but only at specified values, corresponding in this experiment to just a single quantum of angular momentum. A focused laser beam creates the circuit element—a barrier across one side of the ring. The barrier constitutes a tunable "weak link" that can turn off the current around the loop.

Superflow stops abruptly when the strength of the barrier is sufficiently high. Like water in a pinched garden hose, the atoms speed up in the vicinity of the barrier. But when the velocity reaches a critical value, the atoms encounter resistance to flow (viscosity) and the circulation stops, as there are no external forces to sustain it.

In atomic Bose-Einstein condensates, researchers have previously created Josephson junctions, a thin barrier separating two superfluid regions, in a single atomic trap. SQUIDs require a Josephson junction in a circuit. This present work represents the implementation of a complete atom circuit, containing a superfluid ring of current and a tunable weak link barrier. This is an important step toward realizing an atomic SQUID analog.

* A. Ramanathan, K. C. Wright, S. R. Muniz, M. Zelan, W. T. Hill III, C. J. Lobb, K. Helmerson, W. D. Phillips and G. K. Campbell. Superflow in a toroidal Bose-Einstein condensate: an atom circuit with a tunable weak link. Physical Review Letters. Published online March 28, 2011.

####

For more information, please click here

Contacts:
Ben Stein

301-975-3097

Copyright © NIST

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

Roll up your screen and stow it away? Tel Aviv University researchers develop molecular backbone of super-slim, bendable digital displays March 30th, 2015

Princess Margaret scientists convert microbubbles to nanoparticles: Harnessing light to advance tumor imaging, provide platform for targeted treatment March 30th, 2015

Wrapping carbon nanotubes in polymers enhances their performance: Scientists at Japan's Kyushu University say polymer-wrapped carbon nanotubes hold much promise in biotechnology and energy applications March 30th, 2015

Tokyo Institute of Technology research: Catalyst redefines rate limitations in ammonia production March 30th, 2015

Physics

Next important step toward quantum computer: Scientists at the University of Bonn have succeeded in linking 2 different quantum systems March 30th, 2015

A first glimpse inside a macroscopic quantum state March 28th, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

Thousands of atoms entangled with a single photon: Result could make atomic clocks more accurate March 26th, 2015

Chip Technology

Next important step toward quantum computer: Scientists at the University of Bonn have succeeded in linking 2 different quantum systems March 30th, 2015

State-of-the-art online system unveiled to pinpoint metrology software accuracy March 27th, 2015

SUNY POLY CNSE to Host First Ever Northeast Semi Supply Conference (NESCO) Conference Will Connect New and Emerging Innovators in the Northeastern US and Canada with Industry Leaders and Strategic Investors to Discuss Future Growth Opportunities in NYS March 25th, 2015

NXP and GLOBALFOUNDRIES Announce Production of 40nm Embedded Non-Volatile Memory Technology: Co-developed technology to leverage GLOBALFOUNDRIES 40nm process technology platform March 24th, 2015

Sensors

UW scientists build a nanolaser using a single atomic sheet March 24th, 2015

Iranian Researchers Present Model to Determine Dynamic Behavior of Nanostructures March 24th, 2015

Nanodevice Invented in Iran to Detect Hydrogen Sulfide in Oil, Gas Industry March 20th, 2015

LamdaGen Corporation Launches Taiwan Diagnostic Subsidiary March 19th, 2015

Nanoelectronics

SUNY POLY CNSE to Host First Ever Northeast Semi Supply Conference (NESCO) Conference Will Connect New and Emerging Innovators in the Northeastern US and Canada with Industry Leaders and Strategic Investors to Discuss Future Growth Opportunities in NYS March 25th, 2015

UW scientists build a nanolaser using a single atomic sheet March 24th, 2015

Iranian Researchers Present Model to Determine Dynamic Behavior of Nanostructures March 24th, 2015

Sharper nanoscopy: What happens when a quantum dot looks in a mirror? March 19th, 2015

Discoveries

Roll up your screen and stow it away? Tel Aviv University researchers develop molecular backbone of super-slim, bendable digital displays March 30th, 2015

Princess Margaret scientists convert microbubbles to nanoparticles: Harnessing light to advance tumor imaging, provide platform for targeted treatment March 30th, 2015

Wrapping carbon nanotubes in polymers enhances their performance: Scientists at Japan's Kyushu University say polymer-wrapped carbon nanotubes hold much promise in biotechnology and energy applications March 30th, 2015

Next important step toward quantum computer: Scientists at the University of Bonn have succeeded in linking 2 different quantum systems March 30th, 2015

Announcements

Princess Margaret scientists convert microbubbles to nanoparticles: Harnessing light to advance tumor imaging, provide platform for targeted treatment March 30th, 2015

Wrapping carbon nanotubes in polymers enhances their performance: Scientists at Japan's Kyushu University say polymer-wrapped carbon nanotubes hold much promise in biotechnology and energy applications March 30th, 2015

Tokyo Institute of Technology research: Catalyst redefines rate limitations in ammonia production March 30th, 2015

Next important step toward quantum computer: Scientists at the University of Bonn have succeeded in linking 2 different quantum systems March 30th, 2015

Research partnerships

'Atomic chicken-wire' is key to faster DNA sequencing March 30th, 2015

SUNY Poly & M+W Make Major Announcement: Major Expansion To Include M+W Owned Gehrlicher Solar America Corporation That Will Create up to 400 Jobs to Develop Solar Power Plants at SUNY Poly Sites Across New York State March 26th, 2015

ORNL-led team demonstrates desalination with nanoporous graphene membrane March 25th, 2015

New kind of 'tandem' solar cell developed: Researchers combine 2 types of photovoltaic material to make a cell that harnesses more sunlight March 24th, 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