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The Vacuum Transistor: A Device Made of Nothing

spectrum.ieee.org

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Re: The Vacuum Transistor: A Device Made of Nothing

#51

Post by marcosdumay »

spiritplumber wrote: post #39
xellisx wrote: post #38

Earlier quoted context omitted.

They already do. Check out Line6.com

Won't prevent audiophiles from being audiophiles. I remember reading a screed against double-blind testing on some magazine (would link to, but can't find it)

Audiophiles are funny.

I had a huge problem of making an D/A converter with enough precision for instrumentation a while back, but designing some digital I/O with enough bandwidth for it was a nightmare. Then I looked at the Internet and saw an audiophile complaining that a soundcard[1] with 20dB less noise than my design was crap.

1 - A PCI express card, of course. Didn't try that bus. I'd have a really bad time manualy creating a board for it.

Re: The Vacuum Transistor: A Device Made of Nothing

#52

Post by marcosdumay »

cfallin wrote: post #41
marcosdumay wrote: post #32

Earlier quoted context omitted.

You can have 5x the voltage without changing the power consumption if you reduce the capacitance. If you keep the transistors at the same size, a computer working with 5x mode voltage will use 5x more power if operating at the same frequency. (But you can probably make it run faster...) That said, except for very few embedded applications, computers today operate on a voltage that's much bigger than the silicon band…

Actually, all else being constant, 5x voltage yields 25x power: P = CV^2 * f (multiply by activity factor if pedantic; assuming all transistors toggle every cycle here.)

And, of course, you are right.

Re: The Vacuum Transistor: A Device Made of Nothing

#53

Post by typon »

valarauca1 wrote: post #46
kken wrote: post #40

Earlier quoted context omitted.

>The problem is with carbon in general is it has a band gap The band gap is not a function of the element alone, but mainly of the crystal structure. Different allotropes of carbon have vastly different band structures. Diamond has a high band gap, as you mentioned. But Graphene has none, and that is one of the major obstacles of the material.

The problem with having none is that makes your transistors even more vulnerable to quantum effects.

That's not the main problem. The main problem of not having a bandgap is that you don't have a transistor...

Re: The Vacuum Transistor: A Device Made of Nothing

#54

Post by typon »

danparsonson wrote: post #45

How does one speed-test a device that switches significantly faster than the available electronics?

It is not even the fastest. This article did well to leave out actually fast transistors, only comparing to graphene transistors which most people don't really consider fast in the first place.

Checkout Indium Phosphide HEMTs (High electron mobility transistors): http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4419013

Mark Rodwell's group in UCSB (http://www.ece.ucsb.edu/Faculty/rodwell/rodwell_info/rodwell...) has been working on these transistors for a while. I think they're pushing 2 THz currently.

Re: The Vacuum Transistor: A Device Made of Nothing

#55

Post by kken »

typon wrote: post #53
valarauca1 wrote: post #46

Earlier quoted context omitted.

The problem with having none is that makes your transistors even more vulnerable to quantum effects.

That's not the main problem. The main problem of not having a bandgap is that you don't have a transistor...

Sshhh.. It's not allowed to talk in that way about the graphene "transistor". You may upset certain funding sources.

But you know, it is really fast! Just almost useless transconductance and no off state, but we can fix it later!

Re: The Vacuum Transistor: A Device Made of Nothing

#56

Post by typon »

kken wrote: post #55
typon wrote: post #53

Earlier quoted context omitted.

That's not the main problem. The main problem of not having a bandgap is that you don't have a transistor...

Sshhh.. It's not allowed to talk in that way about the graphene "transistor". You may upset certain funding sources. But you know, it is really fast! Just almost useless transconductance and no off state, but we can fix it later!

But bilayer graphene has an induced bandgap!! What? The mobility goes to shit as soon as you touch it with a substrate? Well that's not a problem, we'll design vacuum suspended GFETs, but I'll get right back to you when I figure out how to put an oxide around that sucker
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