The quantum Zeno effect.

[Sorcerer]

I was just reading this article

http://www.nanowerk.com/nanotechnology-news/newsid=41662.php

 

I was only able to read the referenced papers abstract, what I want to know is how they know if/when an atom tunneled? What measure of change shows this happened? How can tunnelling be distinguished from movement of a more local atom, if the atoms are identical how can they be sure?

I'm just beginning some reading on quantum tunnelling https://en.m.wikipedia.org/wiki/Quantum_tunnelling

 

I'm wondering if anyone knows what the classically insurmountable barrier is here, there is no mention of it in the article. Is it the lasers which contain the lattice?

 

My reading leads me to a question, is there a standard moment of time in quantum mechanics, if not surely there must be a gap between measurements and they cannot be continuous, why didn't any atoms tunnel then?

 

It seems stupid I guess because it's indistinguishable from the simpler alternative, but why can't the atoms tunnel out and back between measurement and so appear not to move?

 

Could it be interpreted that the atoms actually have tunneled and the measurement is a quantum shadow/ghost, an artefact of the experiment being observed simply because energy is being expended on retaining a measurement which is no longer current?

 

Is the anything wrong with an interpretation where the atoms exist in a superposition of tunneled and not tunneled? And we are just biased by a prior measurement to assuming they're in the former state?

 

Are any of these questions/ideas testable/falsifiable have any of them been the subject of experiment yet?

[swansont]

I was just reading this article

http://www.nanowerk.com/nanotechnology-news/newsid=41662.php

 

I was only able to read the referenced papers abstract, what I want to know is how they know if/when an atom tunneled? What measure of change shows this happened? How can tunnelling be distinguished from movement of a more local atom, if the atoms are identical how can they be sure?

I'm just beginning some reading on quantum tunnelling https://en.m.wikipedia.org/wiki/Quantum_tunnelling

 

 

Arxiv version of the paper (or closely related one) http://arxiv.org/pdf/1411.2678v1.pdf

 

The atoms are in a lattice with a reasonably high filling fraction of ~0.25, which means that some sites are populated by more than one atom. When that happens there is photoassociation, and the dimer produced is no longer trapped, so it represents a loss from the system. So that's what they measured — the decrease in fluorescence from their probe meant that there were losses, and that rate is a proxy for the tunneling rate.

Is the anything wrong with an interpretation where the atoms exist in a superposition of tunneled and not tunneled? And we are just biased by a prior measurement to assuming they're in the former state?

 

Since you're measuring whether they've tunneled or not, they can't be in a superposition.