Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST atom interferometry displays new quantum tricks

30.05.2007
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated a novel way of making atoms interfere with each other, recreating a famous experiment originally done with light while also making the atoms do things that light just won't do.

Their experiments showcase some of the extraordinary behavior taken for granted in the quantum world—atoms acting like waves and appearing in two places at once, for starters—and demonstrate a new technique that could be useful in quantum computing with neutral atoms and further studies of atomic hijinks.

The NIST experiments, described in Physical Review Letters,* recreate the historic "double-slit" experiment in which light is directed through two separate openings and the two resulting beams interfere with each other, creating a striped pattern. That experiment is a classic demonstration of light behaving like a wave, and the general technique, called interferometry, is used as a measurement tool in many fields. The NIST team used atoms, which, like light, can behave like particles or waves, and made the wave patterns interfere, or, in one curious situation, not.

Atom interferometers have been made before, but the NIST technique introduces some new twists. The researchers trap about 20,000 ultracold rubidium atoms with optical lattices, a lacework of light formed by three pairs of infrared laser beams that sets up an array of energy "wells," shaped like an egg carton, that trap the atoms. The lasers are arranged to create two horizontal lattices overlapping like two mesh screens, one twice as fine as the other in one dimension. If one atom is placed in each site of the wider lattice, and those lasers are turned off while the finer lattice is activated, then each site is split into two wells, about 400 nanometers apart. Under the rules of the quantum world, the atom doesn't choose between the two sites but rather assumes a "superposition," located in both places simultaneously. Images reveal a characteristic pattern as the two parts of the single superpositioned atom interfere with each other. (The effect is strong enough to image because this is happening to thousands of atoms simultaneously—see image.)

Everything changes when two atoms are placed in each site of the wider lattice, and those sites are split in two. The original atom pair is now in a superposition of three possible arrangements: both atoms on one site, both on the other, and one on each. In the two cases when both atoms are on a single site, they interact with each other, altering the interference pattern—an effect that does not occur with light. The imbalance among the three arrangements creates a strobe-like effect. Depending on how long the atoms are held in the lattice before being released to interfere, the interference pattern flickers on (with stripes) and off (no stripes). A similar "collapse and revival" of an interference pattern was seen in similar experiments done earlier in Germany, but that work did not confine a pair of atoms to a single pair of sites. The NIST experiments allowed researchers to measure the degree to which they had exactly one or exactly two atoms in a single site, and to controllably make exactly two atoms interact. These are important capabilities for making a quantum computer that stores information in individual neutral atoms.

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov/public_affairs/quantum/quantum_info_index.html

More articles from Physics and Astronomy:

nachricht Tangled magnetic fields power cosmic particle accelerators
14.12.2018 | DOE/SLAC National Accelerator Laboratory

nachricht In search of missing worlds, Hubble finds a fast evaporating exoplanet
14.12.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>