Tag Archives: JQI

With a song in your heart and multiplexed images in an atomic vapor

A specific piece of research has inspired a song with lyrics based on the text of a research paper and, weirdly, it works. You will have a song in your heart and on your lips and it’s all to do with storing images in an atomic vapor,

Hot, hot, hot, eh?

As for the research paper itself (Temporally multiplexed storage of images in a Gradient Echo Memory), it’s currently availab.e at arXiv.org or in Optics Express, Vol. 20, Issue 11, pp. 12350-12358 (2012) DOI: 10.1364/OE.20.012350(authors: Quentin Glorieux, Jeremy B. Clark, Alberto M. Marino, Zhifan Zhou, Paul D. Lett). The May 29, 2012 news item on Nanowerk offers some tantalizing tidbits about the work,

The storage of light-encoded messages on film and compact disks and as holograms is ubiquitous—grocery scanners, Netflix disks, credit-card images are just a few examples. And now light signals can be stored as patterns in a room-temperature vapor of atoms. Scientists at the Joint Quantum Institute [JQI] have stored not one but two letters of the alphabet in a tiny cell filled with rubidium (Rb) atoms which are tailored to absorb and later re-emit messages on demand. This is the first time two images have simultaneously been reliably stored in a non-solid medium and then played back.

In effect, this is the first stored and replayed atomic movie. Because the JQI researchers are able to store and replay two separate images, or “frames,” a few micro-seconds apart, the whole sequence can qualify as a feat of cinematography.

Here’s a little more detail about how this was done and some information about the implications,

Having stored one image (the letter N), the JQI physicists then stored a second image, the letter T, before reading both letters back in quick succession. The two “frames” of this movie, about a microsecond apart, were played back successfully every time, although typically only about 8 percent of the original light was redeemed, a percentage that will improve with practice. According to Paul Lett, one of the great challenges in storing images this way is to keep the atoms embodying the image from diffusing away. The longer the storage time (measured so far to be about 20 microseconds) the more diffusion occurs. The result is a fuzzy image.

Paul Lett plans to link up these new developments in storing images with his previous work on squeezed light. “Squeezing” light is one way to partially circumvent the Heisenberg uncertainty principle governing the ultimate measurement limitations. By allowing a poorer knowledge of a stream of light—say the timing of the light, its phase—one gain a sharper knowledge of a separate variable—in this case the light’s amplitude. This increased capability, at le ast for the one variable, allows higher precision in certain quantum measurements.

“The big thing here,” said Lett, “is that this allows us to do images and do pulses (instead of individual photons) and it can be matched (hopefully) to our squeezed light source, so that we can soon try to store “quantum images” and make essentially a random access memory for continuous variable quantum information. The thing that really attracted us to this method—aside from its being pretty well-matched to our source of squeezed light—is that the ANU [Australian National University] group was able to get 87% recovery efficiency from it – which is, I think, the best anyone has seen in any optical system, so it holds great promise for a quantum memory.”

I may never totally understand this work but at least I now have a song to sing and for anyone who wants more details, the May 27, 2012 news item on Nanowerk provides details and images, as well as, another opportunity to watch the song.  I did check out the video on YouTube and found that it’s by therockcookiebottom and is part of a project, Song A Day: 1000 Days and Counting that singer-songwriter, Jonathan Mann started in Jan. 2009. I imagine that means he  must be nearing the end. Thank you Jonathan for a very entertaining and educational song. He does offer memberships to support him and his song-a-day project and opportunities to hire him for any songwriting projects you may have.

Quantum kind of day: metaphors, language and nanotechnology

I had a bonanza day on the Nanowerk website yesterday as I picked up three items, all of which featured the word ‘quantum’ in the title and some kind of word play or metaphor.

From the news item, Quantum dots go with the flow,

Quantum dots may be small. But they usually don’t let anyone push them around. Now, however, JQI [Joint Quantum Institute] Fellow Edo Waks and colleagues have devised a self-adjusting remote-control system that can place a dot 6 nanometers long to within 45 nm of any desired location. That’s the equivalent of picking up golf balls around a living room and putting them on a coffee table – automatically, from 100 miles away.

There’s a lot of detail in this item which gives you more insight (although the golf ball analogy does that job very well) into just how difficult it is to move a quantum dot and some of the problems that had to be solved.

Next, A quantum leap for cryptography,

To create random number lists for encryption purposes, cryptographers usually use mathematical algorithms called ‘pseudo random number generators’. But these are never entirely ‘random’ as the creators cannot be certain that any sequence of numbers isn’t predictable in some way.

Now a team of experimental physicists has made a breakthrough in random number generation by applying the principles of quantum mechanics to produce a string of numbers that is truly random.

‘Classical physics simply does not permit genuine randomness in the strict sense,’ explained research team leader Chris Monroe from the Joint Quantum Institute (JQI) at the University of Maryland in the US. ‘That is, the outcome of any classical physical process can ultimately be determined with enough information about initial conditions. Only quantum processes can be truly random — and even then, we must trust the device is indeed quantum and has no remnant of classical physics in it.’

This is a drier piece (I suspect that’s due to the project itself) so the language or word play is in the headline. I immediately thought of a US tv series titled, Quantum Leap where, for five seasons, a scientist’s personality/intellect/spirit is leaping into people’s bodies, randomly through time. There are, according to Wikipedia, two other associations, a scientific phenomenon and a 1980s era computer. You can go here to pursue links for the other two associations. This is very clever in that you don’t need to have any associations to understand the base concept in the headline but having one or more association adds a level or more of engagement.

The final item, Scientists climb the quantum ladder,

An EU [European Union]-funded team of scientists from Cardiff University in the UK has successfully fired photons (light particles) into a small tower of semiconducting material. The work could eventually lead to the development of faster computers. …

The scientists, from the university’s School of Physics and Astronomy, said a photon collides with an electron confined in a smaller structure within the tower. Before the light particles re-emerge, they oscillate for a short time between the states of light and matter.

While I find this business of particles oscillating between two different states, light and matter, quite fascinating this particular language play is the least successful. I think most people will do what I did and miss the relationship between the ‘tower’ in the news item’s first paragraph and the ‘ladder’ in the headline. I cannot find any other attempt to play with either linguistic image elsewhere in the item.

Given that I’m  a writer I’m going to argue that analogies, metaphors, and word play are essential when trying to explain concepts to audiences that may not have your expertise and that audience can include other scientists. Here’s an earlier posting about some work by a cognitive psychologist, Kevin Dunbar, who investigates how scientists think and communicate.