Electrons go Superballistic

Submitted by PriceRip on Mon, 03/06/2017 - 3:13pm

New research shows that electrons passing through a narrow constriction in a piece of metal can move much faster than expected, and that they move faster if there are more of them — a seemingly paradoxical result.

The result is that, through a sufficiently narrow, point-like constriction in a metal, electrons can flow at a rate that exceeds what had been considered a fundamental limit, known as Landauer’s ballistic limit.

Missing from the article from which I lifted these quotations is that in 1957, Rolf Landauer treated the electrons as individual interacting particles. Electrons in close proximity to each other exhibit bulk rather than individual behavior.

Atomic structure is not a miniature solar system with individual electrons orbiting a compact nucleus. Nuclear and atomic processes are not mutually isolated so we have no reason to think a collection of electrons in an atom or in a constricted space act as mutually isolated individual particles.

So, while I had no reason to suspect this particular result in a metal, the result is not "Earthshaking", just as quantum tunneling is no longer thought of as surprising. The researches should be commended for finding an result that will, no doubt, be very important in the design of the next generation of computers if not a breakthrough finding in the development of quantum computers.

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Basic Particle Physics

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Submitted by k9disc on Mon, 03/06/2017 - 7:37pm

Love Your Sciency Stuff, PR. Wish We Could Hang Out and Chat

about it. Right fucking over my head, nearly all the time. I would have to talk and share information to catch the net.

We'll be in the Pac NW this summer. Maybe we could hook up in OR.

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“Tactics without strategy is the noise before defeat.” ~ Sun Tzu

Submitted by PriceRip on Mon, 03/06/2017 - 9:42pm

Sounds like a plan.

@k9disc

I plan to hang out, rather than travel, this summer. Living in a real mountain valley is awesome after such a long time at the edge of the high plains.

Submitted by Not Henry Kissinger on Tue, 03/07/2017 - 9:48am

Greater efficiency through self organization?

In a passageway of a given size, if there are few gas molecules, they can travel unimpeded in straight lines. This means if they are moving at random, most of them will quickly hit the wall and bounce off, losing some of their energy to the wall in the process and thus slowing down every time they hit. But with a bigger batch of molecules, most of them will bump into other molecules more often than they will hit the walls. Collisions with other molecules are “lossless,” since the total energy of the two particles that collide is preserved, and no overall slowdown occurs. “Molecules in a gas can achieve through ‘cooperation’ what they cannot accomplish individually,” he says.

As the density of molecules in a passageway goes up, he explains, “You reach a point where the hydrodynamic pressure you need to push the gas through goes down, even though the particle density goes up.” In short, strange as it might seem, the crowding makes the molecules speed up.

I'm a big believer in equilibration. My take is that as the electrons interact they start to take on similar motion characteristics, homogenizing their states and allowing for greater efficiency than diffuse electrons in more random states.

As with most things quantum, the key may lie the spin of the electrons as they self organize. It would be interesting to know how the spins of the electrons line up as they pass through the slit. My guess is it's a self reinforcing process: the more the electrons interact, the more uniform the spins become, which in turn leads to greater efficiency and thus greater linear speed. Rinse/repeat.

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The current working assumption appears to be that our Shroedinger's Cat system is still alive. But what if we all suspect it's not, and the real problem is we just can't bring ourselves to open the box?

Submitted by PriceRip on Tue, 03/07/2017 - 1:24pm

Damn, I wish I had had this thought!

@Not Henry Kissinger

It would be interesting to know how the spins of the electrons line up as they pass through the slit.

Self-organization inducing some functional cooper pairing. Nowhere (but from you) did I see that thought expressed.

In "normal" superconductivity cooper pairs are "disrupted" by lattice vibrations, hence the temperature dependance. This phenomenon involves bypassing the bulk of the lattice so we would not expect the same temperature dependance.