Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Physics

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

An Archimedes' screw for groups of quantum particles November 19th, 2016

Trickling electrons: Close to absolute zero, the particles exhibit their quantum nature November 10th, 2016

Chip Technology

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Sensors

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Tip-assisted chemistry enables chemical reactions at femtoliter scale November 16th, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Nanoelectronics

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Journal Nanotechnology Progress International (JONPI) Volume 6, issue 2 coming out soon! December 5th, 2016

Supersonic spray yields new nanomaterial for bendable, wearable electronics: Film of self-fused nanowires clear as glass, conducts like metal November 23rd, 2016

Discoveries

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Announcements

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Research partnerships

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Quantum obstacle course changes material from superconductor to insulator December 1st, 2016

Novel silicon etching technique crafts 3-D gradient refractive index micro-optics November 28th, 2016

Single photon converter -- a key component of quantum internet November 28th, 2016

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