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."

Comments

access

[game kid]

So far, researchers in Germany have achieved 10ns access times and 0.7Hz refresh rates

Who's accessing my dots??? ...are you accessing my dots?

Just What Is A .7 Hz Refresh Rate?

[Nom du Keyboard]

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.

Re:Just What Is A .7 Hz Refresh Rate?

[jimdread]

According to the article, the 0.7Hz refresh rate is what they need now with the experimental dots. The researchers predict that in the future they'll be able to make dots with a refresh rate of 3.17 * 10^-14 Hz, or one refresh every 1 million years.

Re:Just What Is A .7 Hz Refresh Rate?

[Anonymous Coward]

The article isn't very clear, but it appears to be saying that they have created experimental models with 0.7Hz refresh rates and 10ns access times, but they predict that quantum dots of different compositions could preserve the access time without a need for refresh (actually, for "one million years," although I think the writer was pulling that number out of his ass).

Re:Just What Is A .7 Hz Refresh Rate?

[PacoTaco]

Just what is a .7 refresh rate?

Crysis on a 486.

Explore?

[michaelmalak]

Researchers Explore Quantum Dot Based NVRAM

You are in a maze of twisty little passages, all alike.

Re:Explore?

[heinousjay]

Yes.

I've said it before...

[Jafafa Hots]

...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.

Strange suimmary

[niceone]

10ns access times and 0.7Hz refresh rates. Their calculations predict that the access time could be maintained for up to a million years.

What TFA says is that at the moment the memory needs refreshing at 0.7Hz, but they calculate that eventually they'll be able to make one that only needs refreshing once every million years.

This technology would have come out sooner...

[MobileTatsu-NJG]

... but it was suspended for nearly a decade after the head researcher stepped into the accelerator... and vanished.

have they solved QD blinking yet?

[davidknippers]

Given that quantum dot 'blinking' seems to be stochastic, I don't see how quantum dots could be utilized for reliable RAM.

Re:have they solved QD blinking yet?

[davidknippers]

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...

Re:have they solved QD blinking yet?

[BeanThere]

The resarch and funding IS to figure out and then solve (if possible) the problems still associated with QDs ... duh. It's been exactly the same with every other technology (and/or other potentially interesting line of research) in the entire history of humanity, why should this be different? Do you rather expect all the problems to be solved instantly by researchers before they ever get funding? If the problems were already solved, no research would be necessary ... funding isn't a prize you get after you've solved a problem, it is a necessary requirement of setting about solving a problem.

MS-DOS + Dots

[cadeon]

General failure reading dots.
Abort, Retry, Fuse?

Story wrong: This is volatile memory

[gweihir]

As could have easily be seen by the "refresh rate". Non-volatile memory cannot have a refresh rate.

Memory refresh means to read all cells and write them again with btheir value. This is done to neutralize signal decay. All memory that need refresh looses its stored contents over time, and hence is volatile.