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Physics – Tiny Steps and Giant Leaps

Sub-atomic physics is about the coolest shit ever. The single photon / double slit experiment – the thing that first made me say, “Wow!” in the world in science – still blows me away, and the work being done in the minds and labs of physicists (the branch of science that has the most fun…except, perhaps for the psychs working with LSD) is truly awesome.

Comes this story out of Caltech:

Viennese physicist Anton Zeilinger, in groundbreaking experiments in 1999, found that molecules as large as buckyballs exhibit the wave-particle duality of atoms…Physicists keep pushing the envelope, trying to see how large of an object they can catch showing quantum effects.

Now, post-doc Matt LaHaye and his colleagues at the California Institute of Technology have built a miniature structure that can help them detect whether an object made of 10 billion atoms exhibits quantum properties. The specific property currently under study is a phenomenon called “quantized energy.” On the human scale, oscillating objects, like a pendulum, have a continuous energy curve, progressing from 100 percent of their possible energy to zero and back. But atoms oscillate between clear energy states—for example, an atom could have 100 percent energy or zero, but nowhere in between. They have quantized energy.

On a silicon chip, they have created, side by side, a nanoscale aluminum bridge and a small loop of superconductor (a “Cooper pair box”) that acts like an artificial “atom.” This “atom” serves as a “qubit,” taking one of two states, like a quantum version of the binary bits in a computer. The bridge—made of 10 billion atoms—vibrates side to side when a current is applied, while the qubit jumps between its energy levels. Both generate electric fields, which are so close that they in turn interact with each other, allowing the movement of the bridge to telegraph the energy levels of the qubit.

The researchers’ first test, published recently in Nature, is a proof of principle: If they could deduce the atom’s quanta from the bridge’s vibrations, they would have proof that they could turn the experiment around and use the atom’s vibrations to measure the quanta of the bridge. And lo and behold, nested within the readouts from the bridge were the signatures of the qubit state, clear as day.

“These experiments sound like thought experiments you see in books, ones that when you build them won’t work,” Schwab says. “But what we’re realizing is that these work.”

With improvements to their technique, the researchers hope to probe the quanta of the bridge from the readout of the qubit. If they find quantum effects in their bridge, it will be the largest object yet to show them, a major breakthrough. And from there, the prospective experiments are exhilarating: By engineering even tighter coupling between the qubit and the bridge, the researchers hope to be able to probe whether the vibrating bridge exists in two places at once, a strange quantum property called superposition.

Within the physics community, the Caltech results have been viewed with interest. In a recent Nature editorial, Finnish physicists Pertti Hakonen and Mika A. Sillanpää admire the extreme delicacy of the measurements, remarking that this is “an important step,” and suggesting that quantum effects in macroscale moving objects could be achieved within a decade. Markus Aspelmeyer, of Zeilinger’s group in Austria, calls the work “very beautiful and demanding,” and says that the team has “an extremely promising system” for observing quantum effects. Schwab says that the number of physicists who take it for granted that the experiments will succeed has surprised him: “The primary criticism is, ‘You’ll succeed—then what?’”

Then what, indeed. THIS is why it’s important to keep stupid creationist crap out of the science classroom. Not only are these experiments far more fascinating and inspiring than any pat, “Because God willed it so,” reasoning, but the dogmatic “Answers in Genesis approach to understanding the world obstructs even the investigation.


One Response

  1. I have to admit my reading of scientific literature has declined since I began as a biology major in college, oh, so many ages ago, but superposition still intriques me like few subjects do. Quantum mechanics is such a remarkable endeavor to behold that it makes the universe more beautiful and magnificent than hearing, “God said let there be light and it was so”. The application of this kind of research seems to me to be limitless, to answer the question of “–then what?”

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