Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > More certainty on uncertainty's quantum mechanical role: Researchers present findings at Frontiers in Optics 2012 that observation need not disturb systems as much as once thought, severing the act of measurement from the Heisenberg Uncertainty Principle

A general method for measuring the precision and disturbance of any system. The system is weakly measured before the measurement apparatus and then strongly measured afterwards.

Credit: Lee Rozema, University of Toronto
A general method for measuring the precision and disturbance of any system. The system is weakly measured before the measurement apparatus and then strongly measured afterwards.

Credit: Lee Rozema, University of Toronto

Abstract:
Scientists who study the ultra-small world of atoms know it is impossible to make certain simultaneous measurements, for example finding out both the location and momentum of an electron, with an arbitrarily high level of precision. Because measurements disturb the system, increased certainty in the first measurement leads to increased uncertainty in the second. The mathematics of this unintuitive concept - a hallmark of quantum mechanics - were first formulated by the famous physicist Werner Heisenberg at the beginning of the 20th century and became known as the Heisenberg Uncertainty Principle. Heisenberg and other scientists later generalized the equations to capture an intrinsic uncertainty in the properties of quantum systems, regardless of measurements, but the uncertainty principle is sometimes still loosely applied to Heisenberg's original measurement-disturbance relationship. Now researchers from the University of Toronto have gathered the most direct experimental evidence that Heisenberg's original formulation is wrong. The results were published online in the journal Physical Review Letters last month and the researchers will present their findings for the first time at the Optical Society's (OSA) Annual Meeting, Frontiers in Optics (FiO), taking place in Rochester, N.Y. Oct. 14 -18.

More certainty on uncertainty's quantum mechanical role: Researchers present findings at Frontiers in Optics 2012 that observation need not disturb systems as much as once thought, severing the act of measurement from the Heisenberg Uncertainty Principle

Washington, DC | Posted on October 4th, 2012

The Toronto team set up an apparatus to measure the polarization of a pair of entangled photons. The different polarization states of a photon, like the location and momentum of an electron, are what are called complementary physical properties, meaning they are subject to the generalized Heisenberg uncertainty relationship. The researchers' main goal was to quantify how much the act of measuring the polarization disturbed the photons, which they did by observing the light particles both before and after the measurement. However, if the "before shot" disturbed the system, the "after shot" would be tainted.

The researchers found a way around this quantum mechanical Catch-22 by using techniques from quantum measurement theory to sneak non-disruptive peeks of the photons before their polarization was measured. "If you interact very weakly with your quantum particle, you won't disturb it very much," explained Lee Rozema, a Ph.D. candidate in quantum optics research at the University of Toronto, and lead author of the study. Weak interactions, however, can be like grainy photographs: they yield very little information about the particle. "If you take just a single measurement, there will be a lot of noise in that measurement," said Rozema. "But if you repeat the measurement many, many times, you can build up statistics and can look at the average."

By comparing thousands of "before" and "after" views of the photons, the researchers revealed that their precise measurements disturbed the system much less than predicted by the original Heisenberg formula. The team's results provide the first direct experimental evidence that a new measurement-disturbance relationship, mathematically computed by physicist Masanao Ozawa, at Nagoya University in Japan, in 2003, is more accurate.

"Precision quantum measurement is becoming a very important topic, especially in fields like quantum cryptography where we rely on the fact that measurement disturbs the system in order to transmit information securely," said Rozema. "In essence, our experiment shows that we are able to make more precise measurements and give less disturbance than we had previously thought."

Presentation FW4J.4, "Direct Violation of Heisenberg's Precision Limit by Weak Measurements," takes place Wednesday, Oct. 17 at 2:30 p.m. EDT at the Rochester Riverside Convention Center in Rochester, N.Y.

PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Rochester Riverside Convention Center, Sunday through Thursday, Oct. 14-18. Those interested in obtaining a press badge for FiO should contact OSA's Angela Stark at 202.416.1443 or .

####

About Optical Society of America
Uniting more than 180,000 professionals from 175 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics.

About the Meeting

Frontiers in Optics (FiO) 2012 is the Optical Society's (OSA) 96th Annual Meeting and is being held together with Laser Science XXVIII, the annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. FiO 2012 will also offer a number of Short Courses designed to increase participants' knowledge of a specific subject in the optical sciences while offering the experience of insightful teachers. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at www.FrontiersinOptics.org.

For more information, please click here

Contacts:
Angela Stark

202-416-1443

Copyright © Optical Society of America

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

Strength in numbers: Researchers develop the first-ever quantum device that detects and corrects its own errors March 4th, 2015

New research could lead to more efficient electrical energy storage March 4th, 2015

Energy-generating cloth could replace batteries in wearable devices March 4th, 2015

Arrowhead to Present at 2015 Barclays Global Healthcare Conference March 4th, 2015

Physics

Breakthrough in OLED technology March 2nd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Discoveries

Energy-generating cloth could replace batteries in wearable devices March 4th, 2015

Experiment and theory unite at last in debate over microbial nanowires: New model and experiments settle debate over metallic-like conductivity of microbial nanowires in bacterium March 4th, 2015

Magnetic vortices in nanodisks reveal information: Researchers from Dresden and Jülich use microwaves to read out information from smallest storage devices March 4th, 2015

CiQUS researchers obtain high-quality perovskites over large areas by a chemical method March 4th, 2015

Announcements

Experiment and theory unite at last in debate over microbial nanowires: New model and experiments settle debate over metallic-like conductivity of microbial nanowires in bacterium March 4th, 2015

Magnetic vortices in nanodisks reveal information: Researchers from Dresden and Jülich use microwaves to read out information from smallest storage devices March 4th, 2015

CiQUS researchers obtain high-quality perovskites over large areas by a chemical method March 4th, 2015

Arrowhead to Present at 2015 Barclays Global Healthcare Conference March 4th, 2015

Events/Classes

Arrowhead to Present at 2015 Barclays Global Healthcare Conference March 4th, 2015

Cambrios and Heraeus Jointly Create New, High-Conductivity Transparent Conductors: Two Companies' Combined Products Dramatically Extend Flexible Substrate Capabilities for Next-Generation Mass-Market Technology Products March 3rd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Photonics/Optics/Lasers

Black phosphorus is new 'wonder material' for improving optical communication March 3rd, 2015

Breakthrough in OLED technology March 2nd, 2015

International research partnership tricks the light fantastic March 2nd, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

Quantum nanoscience

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Quantum many-body systems on the way back to equilibrium: Advances in experimental and theoretical physics enable a deeper understanding of the dynamics and properties of quantum many-body systems February 25th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

Exotic states materialize with supercomputers February 12th, 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