Quantum Sensor Developed by LSU Researcher Breaks New Limits

Mar 16, 2010

(PhysOrg.com) -- Researchers at Louisiana State University have invented an optical sensor that surpasses a quantum limit to sensitivity previously believed to be unbeatable. The breakthrough has a broad array of applications, from gravity wave observatories seeking to observe distant and bizarre astrophysical phenomena, to optical gyroscopes used in commercial navigation.

Optical interferometers are some of the most sensitive devices on Earth, and they have a 100 year long history at the forefront of breakthroughs in science - from turn of the century experiments measuring the speed of light and paving the way for Einstein’s - to current day laser interferometer antennas that scan the skies for evidence of emitted from colliding black holes.

Practical applications are navigational gyroscopes found in jet planes and magnetic field sensors used in oil drills. It was previously thought that the there was an ultimate limit on the sensitivity of such devices imposed by the laws of .

“We uncovered this ground breaking new sensor concept in an analysis of optical sensors that exploit some of the stranger predictions of in their workings,” said Jonathon P. Dowling, Hearne Research Chair in Theoretical Physics at LSU and lead researcher on the project.

The LSU team, led by Dowling, has now demonstrated conclusively that this limit can be broken in a work that appeared recently in Physical Review Letters. This work exploits of light to design of the most sensitive optical interferometer ever devised.

“This project began as a research project for one of our physics and astronomy undergraduate students, Gretchen Raterman,” said Dowling. “The work quickly took on a life of its own with different contributions from Ms. Raterman and other members of our LSU team. The end result - the beating of this thought to be unbeatable limit - came as quite a surprise and it illustrates how basic scientific research at LSU can lead to potentially practical advances in technology in unexpected ways.”

Explore further: Quantum holograms as atomic scale memory keepsake

More information: Quantum Metrology with Two-Mode Squeezed Vacuum: Parity Detection Beats the Heisenberg Limit, Phys. Rev. Lett. 104, 103602 (2010). DOI:10.1103/PhysRevLett.104.103602

Related Stories

LIGO once again looking for gravitational waves

Mar 03, 2006

The quest to detect and study gravitational waves with the National Science Foundation-funded Laser Interferometer Gravitational-Wave Observatory, or LIGO, is on again. LIGO is currently conducting its first sustained observational ...

Quantum goes massive

Jul 16, 2009

(PhysOrg.com) -- An astrophysics experiment in America has demonstrated how fundamental research in one subject area can have a profound effect on work in another as the instruments used for the Laser Interferometer ...

Quantum leap for phonon lasers

Feb 22, 2010

Physicists have taken major step forward in the development of practical phonon lasers, which emit sound in much the same way that optical lasers emit light. The development should lead to new, high-resolution ...

Physicists are first to 'squeeze' light to quantum limit

Jan 02, 2009

(PhysOrg.com) -- A team of University of Toronto physicists have demonstrated a new technique to squeeze light to the fundamental quantum limit, a finding that has potential applications for high-precision ...

Nanotechnology Discovery to Make Internet 1000 Times Faster

Aug 12, 2004

Canadian researchers have shown that nanotechnology can be used to pave the way to a supercharged Internet based entirely on light. The discovery could lead to a network 100 times faster than today's. In a study published t ...

Recommended for you

Cooling with molecules

22 hours ago

An international team of scientists have become the first ever researchers to successfully reach temperatures below minus 272.15 degrees Celsius – only just above absolute zero – using magnetic molecules. ...

User comments : 16

Adjust slider to filter visible comments by rank

Display comments: newest first

PinkElephant
5 / 5 (1) Mar 16, 2010
Parity Detection Beats the Heisenberg Limit
Hmm... Let's hear from all the "no hidden variables"/"no fine structure"/"no determinism" people. I wonder how they propose to explain such an outcome, in light of QM's purported completeness...
maxcypher
5 / 5 (2) Mar 16, 2010
At least give us the QM limit to sensitivity and the amount that this new method beats that limit. Also, what is the analysis and which predictions are referred to in the "analysis of optical sensors that exploit some of the stranger predictions"? Physorg is full of such teasers.
jamey
not rated yet Mar 16, 2010
Indeed - what pair of measurements break the Heisenberg Uncertainty relationship in this case? As far as I know, that is the *ONLY* known fundamental limit to observations.
tkjtkj
5 / 5 (1) Mar 17, 2010
"..came as quite a surprise and it illustrates how basic scientific research at LSU can lead to potentially practical advances in technology in unexpected ways.”


Surely there is more room for practical advances in science other than at LSU. More importantly, a presentation without any sort of data or explanation whatsoever is not what we call 'science'.
tkjtkj
not rated yet Mar 17, 2010
".. and it illustrates how basic scientific research at LSU can lead to potentially practical advances in technology in unexpected ways.”

Surely there is more room for practical advances in science other than at LSU. More importantly, a presentation without any sort of data or explanation whatsoever is not what we call 'science'.
Caution
not rated yet Mar 17, 2010
For the love of hyphens!

100-year-long history
current-day laser interferometer antennas
thought-to-be unbeatable limit
frajo
5 / 5 (1) Mar 17, 2010
Quantum Sensor Developed by LSU Researcher Breaks New Limits
I can only conclude that someone invented a "new limit" which lends itself to be broken.
joefarah
3 / 5 (2) Mar 17, 2010
No information in this article. By the way, we set a new record in "Monopoly Deal" today that I thought was unattainable. Tie game! But unlike the article, I can give more detail. My son played a Forced Deal card that gave both he and I a victory at the same time. At least this reply has more info than the article.
fourthrocker
5 / 5 (1) Mar 17, 2010
This article breaks a limit that I thought was unbeatable, lack of detail. The article says almost nothing that can't be known from the title.
CSharpner
not rated yet Mar 17, 2010
I hate reading these so called "articles" with no information. WHAT limit was broken? By how much? Come on Physorg!!

"that gave both he and I a victory"

correction:

"that gave both him and me a victory".

Sorry, that particular grammatical error is a pet peeve of mine. :)
eachus
5 / 5 (1) Mar 17, 2010
I did some Googling and link-following to get to a PDF of the original paper: http://arxiv.org/...42v1.pdf

As far as breaking the Heisenberg limit goes, they show that the traditional understanding of the Heisenberg uncertainty limit applied to the phase of photons from a beam-splitter is incorrect. This "wrong" version of the limit ignores the information in the total number of photons. (Hmmm. Maybe a better way to state it is that the "conventional" understanding looks at the data from pairs of photons. This method looks at the information from all of the photons in an entangled state that pass through the interferometer.)

Read the paper for further details. It really is an exciting result, but it will take years to develop practical interferometers that can take advantage of the new limit.
hush1
not rated yet Mar 17, 2010
The humor displayed here, I find limitless. :)

It's easier to understand than the research quoted. :(
kuro
not rated yet Mar 17, 2010
sounds like really great news for the future amateur telescope makersfrom the bath camp. yay to strehl ratios > 1 ;)
hush1
not rated yet Mar 18, 2010
@kuro

Excuse me? Forgive my myopia! :)

I 'see' no connection between your comment and the article here, as well as the original research paper referenced here.

With all due respect, enlighten me.

I felt encourage with all the humor here to devote
an honest attempt to understand the applied mathematics the authors referenced in their work.
It is not the first time applied mathematics was found to be interpreting physical phenomenon in error, despite peer-review.
mayan
1 / 5 (1) Mar 20, 2010
Laws of Physics can be Designed
When they break the limits to be again broken by some other guy, then whole Q-Mechanics is Broken which implies there is no Q-mechanics, Q-Mechanics is just a property of matter at certain physical conditions, and it shouldnt be taken as final theory....after all its not a theory, which is being broken, laws of Physics can be Designed for eg an electron can be added a property of Anti Gravity apart from its existing properties....
designmemetic
not rated yet Mar 21, 2010
For the love of hyphens!

100-year-long history
current-day laser interferometer antennas
thought-to-be unbeatable limit


LOL