Thermal Logic Gates

Information processing in the world's computers is mostly carried out in compact electronic devices, which use the flow of electrons both to carry and control information. There are, however, other potential information carriers, such as photons, which are parcels of light. Indeed a major industry, photonics, has developed around the sending of messages encoded in pulsed light.
Heat pulses, or phonons, rippling through a crystal might also become a major carrier, says Baowen Li of the National University of Singapore (phylibw@nus.edu.sg). Li, with his colleague Lei Wang, have now shown how circuitry could use heat---energy already present in abundance in electronic devices---to carry and process information.
They suggest that thermal transistors (also proposed by Li's group in Applied Physics Letters, 3 April 2006) could be combined into all the type of logic gates---such as OR, AND, NOT, etc.-used in conventional processors and that therefore a thermal computer, one that manipulates heat on the microscopic level, should be possible.
Given the fact that a solid state thermal rectifier has been demonstrated experimentally in nanotubes by a group at UC Berkeley (Chang et al., Science, 17 November 2006) only a few years after the theoretical proposal of "thermal diode," the heat analog of an electrical diode which would oblige heat to flow preferentially in one direction (Li et al, Physical Review Letters, 29 October 2004). Li is confident that thermal devices can be successfully realized in the foreseeable future.




source:http://www.aip.org/pnu/2007/split/840-2.html

I only know that electrical diode allows current to flow in one direction(rectifying property), however, what's the principle behind?

What is the difference between "thermal diode" and "electrical diode" ? It is only differs in terms of ways of carrying information?(speechless)

Hi,
i don't know much more about this! But i think the logic feature is designing your transistor circuit to conduct based on your desired logic. Typical logic types are AND, NAND, OR, NOR, XOR, etc. A logic gate that is designed to only perform when both and only both inputs are TRUE (high) is an AND gate.

Good day.

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Maybe it allows heat flow only in one direction?

Maybe, it's really interesting.

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Going to face the Hong Kong Advanced-Level Examination which is believed to be the most difficult AL exams in the world this year. I hope good results can be achieved.

From what little we know it looks that such systems cant be very fast and also they look very temperature dependent.

For example if we require a "heat pulse" to go from left to right and due to extraneous reasons the right side temperature goes very high. Then it looks like the thermal diode wont function as expected, whereas for a semiconductor diode this wouldn't be a problem.

Thanks again werehek. I managed to register and look up the article. It is interesting. They dont seem to be considering it as an alternative to semiconductor based logic. However, they mention applications which could be something like walls etc with unidirectional heat flow.

I cant help thinking of the energy savings in heating that can ensue if they can make it commercial.