Are you using spintronics as a synonym for quantum computing?

No, no, they are two different things. I'm glad you asked it. Quantum computing is actually a different kind of computing that we know today which is based on the statistical behavior found in quantum physics. It would be useful for some things but not very useful for the sorts of things we do today.

I think it would be useful for massive calculation but not for today's desktop or laptop computing, right?

Yes, that's right. It offers the potential for a tremendous demand of parallelism, which is very high efficient. But there are only some problems that would be solved with the kind of computing that quantum computers would carry out. What I was talking about was simply using one of the quantum properties, like, you know, charge being 1s, color being 0s. Spin is particularly interesting if we could control these spin effects in new devices of different sorts, and Intel is researching it as well. Returning to Moore's Law, we may reach an end to charge-based electronics in 10 years or 15 years or 20 years, whatever it is. But we replace charge-based electronics with [a] spin-based system. If you declare that will be the end of Moore's Law, I don't know. But as long as we can continue to improve the performance and the energy efficiency and the density we might make that transition.

Now I would like to return to a 40 gigabits transmission, also known as silicon photonics. Could you explain what silicon photonics is?

Sure, It's becoming increasingly difficult to increase data rates when we try to move data over digital copper wire. You know, there is wire on a circuit board; they might be over large distances within a data center or even beyond. As everyone is well aware copper is essentially gone throughout system communications. There are optical fibers extending the globe now. In fact, where I live the telephone company is bringing fiber optics to my house. So, it's becoming de facto for long distance communication. And it is moving closer and closer, beginning to get into the data center. But the cost has been relatively high.

So again, four to five years ago we began to look at the possibility of building these new high-performance optical devices on silicon. And we build high-performance silicon-germanium photodetectors. We build the modulators, starting with 10 gigabits per second and reaching now 40; we've done multiplexers and demultiplexers, and last year we developed a technology called hybrid silicon laser -- we actually build an electrically optical laser. We now are at the point we have light sources, modulators, multiplexers, demultiplexers and detectors. We have a complete end-to-end optical transceiver capability, but we have to put all the devices together on one chip and that's what we are working on right now. What we plan to demonstrate is a complete optical transceiver in silicon over the next year or so.

When will this new technology be available in the marketplace?

Well, it's possible that by the end of the decade we'll have silicon photonic products in the market. If it's not 2010, maybe 2011, but I think we are close ... now.