First-ever photo of light behaving as a wave and particle

boing
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Jokes, too, collapse into when observed too closely.

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blah blah blah physics


I love this stuff.

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Except doesn’t the uncertainty principle mean that if the electron has enough energy to generate a useful image, it pretty much blows the photon to smithereens?

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Hey that’s a two way street, ask me how many holes I’ve had to dig physicists out of because they thought their understanding of quantum mechanics qualified them to develop code and administer a cluster of computing nodes.

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Yeah, Old Physicists don’t die. They just switch to a field they have no expertise in.

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If you read the actual article in Nature, it’s clear that they’re NOT imaging “the particle and wave nature of light”, but rather, the particle and wave nature of surface plasmon polaritons (SPPs) — which are not light, but, rather, oscillations in the ‘electron gas’ of the metal, specifically one particular form of oscillation that propagates on the surface, at the conductor-dielectric interface.

These oscillations can bounce back and forth, being reflected from the ends of the nanowires, which means that nanowires of the right length can create standing waves.

Those standing waves have a detectable field intensity that extends some distance from the wire. Firing electrons through this field allows it to be imaged by the degree of deflection of the electrons.

It’s a very cool thing — and SPPs are very important to information propagation in sub-wavelength structures at the nanoscale, where conventional photonics using light doesn’t work — but it’s NOT a “photo of light behaving as a wave and a particle.”

It’s a photo of a standing wave of surface plasma polaritons behaving as both wave and particle.

(Or at least that’s what the paper in Nature says it is.)

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Here is the paragraph that Cory quotes from the phys.org article, corrected to match what’s actually reported in the Nature article:

The experiment is set up like this: A pulse of laser light is fired at a tiny metallic nanowire. The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels Light induces oscillations called “surface plasma polaritons” (SPPs) in the metal’s delocalized electrons, and these waves of electromagnetic oscillation travel along this tiny wire in two possible directions, like cars on a highway. When waves traveling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment radiating an electromagnetic near field around the nanowire.

This is where the experiment’s trick comes in: The scientists shot a stream of electrons close to the nanowire, using them to image the electric field of the standing wave of light SPPs. As the electrons interacted with the confined light electric field energy on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone’s team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light SPPs.

Of course, by now the phys.org article has been around the web half a dozen times, and everyone believes they’re 'taking pictures of the wave/particle duality of light."

<sigh>

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