Researchers Explore Quantum Dot Based NVRAM
I Don't Believe in Imaginary Property brings us an article describing the possibility of a new type of non-volatile storage based on quantum dot technology. So far, researchers in Germany have achieved 10ns access times and 0.7Hz refresh rates. Their calculations predict that the access time could be maintained for up to a million years. We have discussed other technologies based on quantum dots, such as solar panels and information teleportation. From the Ars Technica article:
"Quantum dots can do this because there is more design freedom in setting them up. Normal flash memory relies on the huge potential barrier created by a silicon oxide layer. However, to get electrons across that barrier when writing data to a flash cell requires a lot of energy, energy that destroys the silicon oxide layer. Quantum dots, in contrast, have tunable properties, so the barrier can be kept low."
Who's accessing my dots??? ...are you accessing my dots?
You can hold down the "B" button for continuous firing.
Just what is a .7 refresh rate? I know what .7 is. I know what Hertz is. And I know what Refresh typically means in a memory system, but if this thing needs constant, albeit slow, refresh, it's hardly non-volatile. It's more like battery backed-up with a very low current drain. Even so, I'd prefer something that was truly stable since power sources do tend to fail at the worst possible times.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
You are in a maze of twisty little passages, all alike.
...and I'll say it again. Quantum dots aren't going to be able to store information until we discover quantum dashes to go along with them.
This space available.
ccalam - acoustic versions of new songs.
I actually can't figure out where all the hype is coming from with quantum dots. They have interesting biomedical applications as fluorophores in cellular imaging and molecular detection. They have advantages to organic dyes traditionally used in imaging applications, as they're tunable, have highly specific emission ranges, very high quantum yields and are resistant to photobleaching. Precise measurements of changes in biomolecules can be measured with quantum dots, such as detection of fluorescence intensity changes of Förster resonance energy transfer processes. However, the use of QDs isn't revolutionary, and they're not exactly cheap to make (a quick trip to the Invitrogen website, searching for their 'QDot' line of products illustrates this). The technical difficulties that still have to be ironed out with quantum dots, such as the 'blinking' problem (likely due to some sort of twist on Auger photoionization) makes them useless in single-molecule excitation situations (which I'm sure would be necessary to control in any sort of storage environment). At this point, numerous problems stand in our way of making them the wonderful solution described in these articles. Their toxicity, steps required to ensure proper surface passivation, limited solubility in aqueous medium without extensive modification to their surface, etc...