A new 'lens' for looking at quantum behavior

December 14, 2011, Macquarie University

A new 'lens' for looking at quantum behaviour
(PhysOrg.com) -- In a paper published in Physical Review Letters, researchers Daniel Terno (Macquarie University, Australia) and Radu Ionicioiu (Institute of Quantum Computing, Canada) provide a new perspective on fundamental notions of quantum physics.

Terno and Radu proposed taking a new approach to understanding wave-particle duality - a cornerstone phenomenon of .

At the heart of is the idea that objects in the will sometimes behave like particles, and other times behave like waves. This ability to combine exclusive properties is called a and is a fundamental principle of quantum mechanics.   

Duality has been the foundation of many ongoing debates in the physics community, the most famous of which was between Albert Einstein and Niels Bohr. Ultimately the issue physicists face is that you can’t observe both wave-like and particle-like properties with a single apparatus.

Terno and Ionicioiu have tried to tackle this issue by asking - what if when performing experiments, parts of the apparatus are absent and present at the same time. What the researchers propose is that you can select the property being tested (wave or particle) even after the test is performed.

Known as a delayed-choice experiment, the photon in this experiment shows a “morphing” between “particle” and “wave,” supporting the conclusion that these properties are not inherent, but merely a reflection on how we “look” at it.

“Unlike the traditional approach, in this quantum-controlled experiment a single set-up is used to measure complementary behaviors, and they are revealed by matching the data about a photon with the data about the apparatus.  What we find is that behavior is in the eye of the observer, ” Terno summarizes.

The intriguing results have caught the attention of science writers around the world, including French journalist Michael Schirber. Schirber recently wrote that this new thought experiment “demonstrates with logical precision the futility of trying to label the photon as a particle or a wave”.

Terno says the thought experiment was designed for exactly this purpose, to look at an old question through a new lens. “We tried to shed some light by looking at the problem from a novel perspective," says Terno. "It was a perfect testing ground for our new tools. Once you get them, you’ll start to apply them to more and more problems, and this is what we are going to do next.”

Explore further: Atom and its quantum mirror image

Related Stories

Observing a Photon no Longer a Seek-and-Destroy Mission

June 2, 2004

A team of University of Queensland, Australia physicists has devised a sophisticated measurement system for single particles of light, or photons, enabling them to investigate fascinating behaviour in the quantum world. ...

Large scale qubit generation for quantum computing

July 27, 2011

(PhysOrg.com) -- "Many people are trying to build a quantum computer," Olivier Pfister tells PhysOrg.com. "One to the problems, though, is that you need hundreds of thousands of qubits. So far, scalability has been something ...

Squeezed light from single atoms

June 30, 2011

(PhysOrg.com) -- Max Planck Institute of Quantum Optics scientists generate amplitude-squeezed light fields using single atoms trapped inside optical cavities.

Recommended for you

Tangled magnetic fields power cosmic particle accelerators

December 13, 2018

Magnetic field lines tangled like spaghetti in a bowl might be behind the most powerful particle accelerators in the universe. That's the result of a new computational study by researchers from the Department of Energy's ...

Stretched quantum magnetism uncovered by quantum simulation

December 13, 2018

By studying ultracold atoms trapped in artificial crystals of light, Guillaume Salomon, a postdoc at the Max-Planck-Institute of Quantum Optics and a team of scientists have been able to directly observe a fundamental effect ...

The secret life of cloud droplets

December 13, 2018

Do water droplets cluster inside clouds? Researchers confirm two decades of theory with an airborne imaging instrument.

Networking goes quantum

December 13, 2018

A scientist involved in expanding quantum communication to a network of users, is continuing his work at the University of Bristol.


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Dec 14, 2011
Just for an abstract injection:

This morning while watching a flock of birds, I was stricken by the similarity of some things I've seen recently.

Audio Reactive Strange Attractors & Coulomb Simulation




Don't know if it means anything, just was driven to post after reading " new perspectives ".

3.7 / 5 (3) Dec 14, 2011
demonstrates with logical precision the futility of trying to label the photon as a particle or a wave

Well, that's because it isn't. That a something exhibites particle-LIKE behavior or wave-LIKE behaviour depending on observation doesn't mean that it is a mix of particle and wave. It is a particle-wave which is a third state that has nothing to do with being particle or wave. The name just suggests similiarity - but that is merely unfortunate nomenclature.
Quantum mechanical entities are described by a wave function with imaginary component.
Only the square of that wave function can be interpreted as the local density probability function. But the original, non squared, form is not a classical wave.
Dec 14, 2011
This comment has been removed by a moderator.
1 / 5 (4) Dec 15, 2011
Particles are just localized standing waves. What is extraordinary is the lack of understanding about nature. Or, speaking historically, Mach. Wikipedia: Mach's principle proposes that mechanics is entirely about relative motion of bodies and, in particular, mass is an expression of such relative motion. So, for example, a single particle in a Universe with no other bodies would have zero mass.

Particles are a residual notion stemming from a Newtonian and Christian conception of absolute time and space. No more real than the god in the sky. For most, sadly, science still has mythological underpinnings. Christianity is a powerful conduit for ignorance.
not rated yet Dec 15, 2011
Does anyone know where the article (It was posted here) where a group used weak interaction forces to track the paths of photons the whole way in a double slit experiment? I can't seem to find it right now. It's seems appropriate that it should be mentioned here.

It was definitely a particle traveling along a wave-like path.

(And in case anyone is confused: this experiment still produced a diffraction pattern)
not rated yet Dec 15, 2011
I'm getting sick of science.


Is it destroying your Bible led view of the Natural World?
1 / 5 (1) Dec 15, 2011
But the original, non squared, form is not a classical wave.
No it's called a phase wave.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.