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Graphene transistor clocked at 427 GHz [pdf]

pnas.org

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Re: Graphene transistor clocked at 427 GHz [pdf]

#31
How would you even sample a signal like that in the real world?

The best Oscilloscopes you can get right now commercially go to about 65GHz using hybrid chips (http://youtu.be/dx596o8t_TY) and cost $500K...

* http://www.home.agilent.com/en/pd-2108888-pn-DSAX96204Q/infi...

Re: Graphene transistor clocked at 427 GHz [pdf]

#32
post #30

For anyone curious why this doesn't translate into a 427GHz computer, light can travel about 1.4mm in one cycle at 427GHz, meaning that all synchronized components would have to be located within 1.4mm of each other. The bottleneck for processor speed became the speed of light some years ago.

I wonder if some the research going on at nasa right now about FTL transportation can be applied at some point?

Re: Graphene transistor clocked at 427 GHz [pdf]

#33

Earlier quoted context omitted.

I suppose we could, but why would we want to?

We would no longer be slaves to the Carnot cycle. Also, you don't need a temperature gradient anymore. Everything warmer than 0K emits thermal radiation. Think free energy for everyone.

This is bullshit (specifically, a perpetual motion machine of the 2nd kind).

Suppose you have a heat source T_H in an environment T_C. If you could extract more work from the thermal radiation of T_H than the Carnot limit for this system, you have enough work to run a Carnot heat pump from T_C to T_H that increases the temperature of T_H, and decreases the temperature of T_C -- an violation of the 2nd law. You could use work to increase the heat source's temperature, leading to more work, leading to higher temperatures, in perpetuum. No can do!

Re: Graphene transistor clocked at 427 GHz [pdf]

#34
post #30

For anyone curious why this doesn't translate into a 427GHz computer, light can travel about 1.4mm in one cycle at 427GHz, meaning that all synchronized components would have to be located within 1.4mm of each other. The bottleneck for processor speed became the speed of light some years ago.

I wonder if some the research going on at nasa right now about FTL transportation can be applied at some point?

I doubt it. As far as I understand it, NASA's research centers around the possibility of deforming spacetime to cause an object to fall through space (sorta).

Deforming spacetime wouldn't really put components closer together, or cause light to travel faster, or anything.

You never know with stuff this weird though. Maybe something else will fall out of their research. It's been known to happen when pushing the boundaries of our understanding of physics.

Re: Graphene transistor clocked at 427 GHz [pdf]

#35
post #34

Earlier quoted context omitted.

I wonder if some the research going on at nasa right now about FTL transportation can be applied at some point?

I doubt it. As far as I understand it, NASA's research centers around the possibility of deforming spacetime to cause an object to fall through space (sorta). Deforming spacetime wouldn't really put components closer together, or cause light to travel faster, or anything. You never know with stuff this weird though. Maybe something else will fall out of their research. It's been known to happen when pushing the bound…

Well if you treat light like an object (if you consider its particle like properties), and deform space-time between the components (or more like deform space-time around the light, so it is of regardless where the components are in euclidean space), wouldn't that theoretically achieve the same thing as making light "move" faster between the components?

Though the way I envision that the components would have be connected by or lie in some kind of vacuum. I mean, these have to be the in the family of tests NASA will have to be conducting on particles before "moving" ships through free space becomes some kind of reality, right?

Re: Graphene transistor clocked at 427 GHz [pdf]

#36
post #34

Earlier quoted context omitted.

I wonder if some the research going on at nasa right now about FTL transportation can be applied at some point?

I doubt it. As far as I understand it, NASA's research centers around the possibility of deforming spacetime to cause an object to fall through space (sorta). Deforming spacetime wouldn't really put components closer together, or cause light to travel faster, or anything. You never know with stuff this weird though. Maybe something else will fall out of their research. It's been known to happen when pushing the bound…

they could be opening the very gates of hell in that lab

Re: Graphene transistor clocked at 427 GHz [pdf]

#37
Nice result. As others have pointed out its not a record or anything, but it is a solid indication that graphene transistors are, in fact, credible. An example of a not really credible transistor are the various organic ones, they have frequency limits in the high kHz to single digit MHz.

But workable graphene transistors gets us one step closer to an all carbon device. Using diamond as a substrate for heat removal, Graphene-on-Diamond (oh snap, those would be GoD devices) could provide for an interesting replacement for more exotic silicon processes. (one could argue that an all carbon process is more exotic still if one chose to).

The benefits over silicon would be faster operation at an equivalent temperature, and the ability to operate at a higher temperature. Pretty much all silicon products melt at a junction temperature around 175 degrees C but carbon based devices should be able to continue to operate well into a few hundred degrees C if I am reading the papers correctly.

Should be an interesting decade.

Re: Graphene transistor clocked at 427 GHz [pdf]

#38
post #30

For anyone curious why this doesn't translate into a 427GHz computer, light can travel about 1.4mm in one cycle at 427GHz, meaning that all synchronized components would have to be located within 1.4mm of each other. The bottleneck for processor speed became the speed of light some years ago.

More to the point, between the cycles of the clock in your CPU a signal has to make it's way across a number of gates. This is usually measured in terms of the equivalent of the time it takes a transistor to drive the capacitances of 4 other transistors (FO4s). Your typical CPU these days will have between 10 to 20 FO4s of delay for each actual clock cycle.

Re: Graphene transistor clocked at 427 GHz [pdf]

#39

How would you even sample a signal like that in the real world? The best Oscilloscopes you can get right now commercially go to about 65GHz using hybrid chips ( http://youtu.be/dx596o8t_TY ) and cost $500K... * http://www.home.agilent.com/en/pd-2108888-pn-DSAX96204Q/infi...

I work in high frequency RF (10s to 100s of GHz). You can use mixers[0] to down convert higher frequency signals and make measurements at lower frequencies.

[0]http://rfic.eecs.berkeley.edu/~niknejad/ee142_fa05lects/pdf/... [pdf]

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