The Material World

Gordon Moore :  In 1965,when Intel founder I was given the job of predicting what would happen in the component industry over the next ten years,and saw that the number of components -that's transistors and resistors we were putting on an integrate circuit had about doubled every year,so I took the rather bold and frankly naive idea,and said "Okay,we're going to do this for another 10 years and at the end of that time,instead of putting 60 components on a chip,we'll be putting 60 thousand components on a chip.

Quentin Cooper : In 1965,when Intel founder Gordon Moore first came up with what became known as "Moore's Law" [see http://members.fortunecity.com/templarser/chess.html & world35.rtf & front14.rtf],he postulated things doubling annually. In the late 70s that time was extended to 18 months,and although the amended law has held good since then -there are now signs of further slow downs,and many physicists believe that within a decade we'll hear Moore's last sigh,as we reach the limits of what available technology can squeeze onto a piece of silicon,which is why some have been approaching the problem from an entirely different angle,and that new bearing is a magnetic one.
To explain how magnetism may replace electricity and lead to us all using magnetic computers in the future,we're joined by Russell Coburn,a nano technologist at Durham University and by Andy Schofield,Professor of Theoretical Physics and expert on spin at Birmingham University,I should say that nanotechnology and spin is going to be central  to getting a handle on this,but Andy Schofield there is something more basic or that we believe that we understand that we really need to explain before we get into all this which is magnetism?

Andy Schofield : Yes magnetism of course has been around for millennia since we..since early man discovered that lodestone would line up with the Earth's magnetic field and always point in the same direction,but the cause of magnetism of course required the discoveries of electricity and we now know that magnetism is generated by moving electronic charge and that can be in the form of currents in a wire,but also there are currents that can occur within an atom and indeed the electron itself can make magnetism all by itself and that's related to a property called "spin" and the spin of an electron and the spin of an electron makes an individual electron behave a little bit like a bar magnet with a north pole and a south pole.

Quentin Cooper : Now when you talk about spin,on this subatomic level is this one of this properties like strangeness and charm (see members.fortunecity.com/templarser/quark.html) which actually don't really correspond to their meanings in the rest of the world,or is it genuinely twisting away down there?

Andy Schofield :  Well it is a theorists or experimentalists word,but if you like to visualise it as an electron actually spinning round,it's not completely correct,but it does capture some of the meaning of it.There's a clockwise rotation or an anticlockwise rotation which is sometimes called hellicity,and the lining up of spin,or a magnetic moment is connected with whether it's going clockwise or anti clockwise.

Quentin Cooper :  So when everything is spinning together,that's...it'll have magnetic properties?

Andy Schofield :   That's right,so when a block of iron goes magnetic ,all of the spins are lining up in the same direction.

Quentin Cooper :  Russell Coburn, as Andy said,we've been exploiting these...the properties of magnetism for thousands of years,but if we want to exploit them for use in computers,we have to go down to a much smaller scale so what begins to happen then?

Russell Coburn : Yes,that's one of the things what we've really discovered in the past decade,that if you make magnets really,and I mean really,really small,close to the size of an atom,they begin to develop very new properties,they don't behave in the same way as a bulk magnet like a fridge magnet of something you'd use to pick your keys up with,but actually behave in a very different sort of way,and fortunately it turns out that that new way is often much more useful and is much more easily to control and to engineer.
[Contrary to your use of grammar which requires a great deal more control by the sound of it - LB]

Quentin Cooper :  Okay, well I thin,talk us through it then,take me down down down to the nano scale.

Russell Coburn :  Okay,well let's start at the top,if you just pick up a lump of iron that you might find lying around the lab,if you looked inside it with a microscope,that could see magnetism,you would see a whole collection of what we call "domains" [Ref: Practical Electronics Apr79  - "Bubble memory"] that means that not all the material is north and south ,but a little region is north and then a little region next to it is south,and so on.

Quentin Cooper :  And what we're experiencing on the larger scale is the overall cumulative effect?

Russell Coburn :   That's right,and usually that cumulative effect is zero,because you've got as much north as you have south,that's why you don't see bits of metal falling across the room towards little bits of iron that are lying around.

Quentin Cooper :   Except in Warner Bros. cartoons yes!

Russell Coburn :    Absolutely! If you...those domains have a certain size to them though,and if you  start to make the magnets small enough that you become comparable to the size of those domains,they start to fall out. Basically there isn't space inside for them anymore.
Now that's quite important because if that happens you don't have an equal balancing,you don't have as much north as you have south,but suddenly the whole thing is north and so it may seem counter-intuitive,but actually a small magnet is much more powerful than a large magnet.

Quentin Cooper :   Now how can you use this,I mean there's two things here,one is actually understanding it,and two is actually being able to apply it,how does this apply in the world of the computer,and why is it going to get us out of this Moore's law bottleneck?

Russell Coburn :    Well, we already are using it,every computer has a hard disk drive,that's the bit that goes whirr clunk when you switch it on,and that is purely magnetic,and that uses  these very small domains that store the ones and zeroes that make up your word file and that contain the program that the computer runs when it starts up.

Quentin Cooper :    So this is practical nanotechnology,we may think this is this wonderful buzzword for the everything's going to be nano in the future, we already heard it when we we're talking about dentistry earlier,but we actually have it if we've got a recent computer sitting around at home as well?

[Domains also exist on magnetic tape - the technology is there - its the theory and the exploitation of it to cram  more data in the same space that's changing - quantum vortices (Ref: Video M3 RI Lecture "Electron Waves") will play a part in that also - perhaps then my 486 will be decomissioned and I'll have a PC that runs at MY speed and not a snail's pace - LB]

Russell Coburn :    Yeah.sort of it's what I would call nanotechnology by accident inasmuch as when these things started the domains were actually quite large,and that's why if you bought a hard disk drive maybe 20-30 years ago you could only store 20-30 megabytes on it - and what's happened is every year,just like in Moore's law there's an equivalent Moore's law in data storage,the size of the domain has shrunk down until by accident it's now a nano scale object and so the hard disk drive as you say,is really a nanotechnology machine.

Quentin Cooper :     Right that's talking about something we've got here,so if we've already got it what's the problem with Moore's law? Why do we need to start talking about entirely magnetic computers?

Russell Coburn :    Well,the dream or the vision that people have got,is that just as magnetism has been so successful at storing data,maybe we can use it more extensively in computers,because a computer doesn't just store information,it also processes it,so this is the memory compared to the microprocessor,say the Intel Pentium or whatever,and around the world a number of researchers including my own research group,are trying to introduce magnetism into the microchips of the computer that currently today are purely electronic. We think that if we can get some magnetism into these electronic chips,then we could overcome some of the limitations of Moore's law.

Quentin Cooper :     And what stage are at?

Russell Coburn :    Well we personally are at a fairly early stage,but a very exciting stage,the computer,although it may seem to be a complex object,essentially it boils down to just a machine that can do two different sums. It can convert the number one into the number zero and the number zero into the number one,so that's an inversion of the number if you like [ A logical NOT - LB].

Quentin Cooper :   Right.

Russell Coburn :    And it can compare two numbers,it can say is one equal to one or is one equal to zero.

[The AND function or a variant of it - when one equals one - then it puts "yes" or 1,if one is not equal it puts "no" or 0

A B   O
0   0    0
0   1    0 
1   0    0
1   1    1 - this is Boolean Logic devised by George Boole - LB]

Now that doesn't sound very advanced,but actually if you can do that....

Quentin Cooper :    If you can combine those two....

Russell Coburn :     If you can combine those two together and do it millions of times in a row,then you can do anything from playing Space Invaders to using Word documents.

Quentin Cooper :     Or even proper things as well,I'm sure there's something bigger to do with computers! But okay,and have you reached the stage where you can get it ...the equivalent of that using magnetism?

Russell Coburn :      We're half way there! We can do what we call the NOT operation,we can do the inversion,we can convert a one to a zero and a zero to a one,now again it doesn't sound that impressive,but it really is halfway towards being able to do everything.

Quentin Cooper :      And if you can do the second one,does everything then fall into place or is there still a lot of other practicalities to sort out?

Russell Coburn :   Well,I'm sure there'll be technical details,but in principle,yes everything then falls into place,you then have access to an entirely new class of computing machine,the way that currently is done by microelectronics, it's all only ever been done by microelectronics. Suddenly you have the potential,if you wish,to start doing it by magnetism.

Quentin Cooper :  Andy it all sounds very nice when you put it like this,but obviously you live more in the theoretical realm, there are...there's many a slip betwixt cup and lip on this sort of thing isn't there?

Andy Schofield :  Yes there is if you're handling spins,then you've got to watch that they don't interact too much with [Quantum decoherence - LB] with the rest of the environment,so that's a worry for the people doing magnetic computers I think. Moreover,at some point you need your magnetism to talk to electricity - to talk to the charge carrying part of the electron and that interface is also an interesting one where new types of things can occur. One example is superconductivity. You can use the spin on an electron as a sort of magnetic glue which sticks electrons together and they form a new state of matter [See members.fortunecity.com/templarser/bose.html - seems to me that Asimov's "positronic brain" is not far off - LB] and so there's the possibility that as we get to a very small scale,as we're able to control what spins are doing and what electrons are doing at the same time,there's the chance that the metal that these things are happening in will change into a completely different state.

Quentin Cooper :  Yes because we're talking about one or two things happening when you get down to the nano scale,but there's a whole raft of strange new properties that start kicking in on this scale,aren't there?

Andy Schofield :   Yes,that's right. Very bizarre things which really have no analogue for electrons on their own,as far as we know,and electron is a completely stable object,you can't separate the magnetism of an electron from its charge. However when you bring a collection of electrons together,it appears,under the right circumstances,that the spin,and the charge of the electron can separate into two completely independent objects. Physicists like to give names to things,we call them the spinon and the holon,these have no independent existence except within this collection of electrons,so I can't isolate a spinon for you and show you it.

[Which begs the question of what a "thing" is that can be named as an object - LB]

But it's one of the strange things that happens at the quantum regime,when you have electron spins and their charges working together.

Quentin Cooper :   And as a theoretical physicist,do you get involved in the practicalities of this? Or do you kind of do the big thinking about the sub atomic world and leave the devices and the techniques to Russell and other people like that?

Andy Schofield :   Well one of the things I like most about my job is that it allows me to talk to people doing experiments and so I  try to work very closely with experimentalists. I enjoy going down to the lab and actually watching the data come in and the reason for that is that that's really motivating all the thinking that we're doing. Nature is much more inventive than us theoretical physicists are,that all the time we're seeing things that we really need to explain,and it's strange when you think that the rules governing electrons have been around for 80 years. We've had the theory of everything as far as the electron is concerned for all this time,yet it's a little bit like chess (see members.fortunecity.com/templarser/chess.html - "The King makes his move") where I've taught my 6 year old how to play chess,the rules are simple enough,but the complexity that can emerge from those rules is fascinating.

[This is why creationists are wrong when they see complexity in the world and think a designer is behind it - LB]

And you know,it takes a lifetime for a grand master to learn and that's where we are really in theoretical physics,some of the basic rules are there - but how they give rise to properties in a real material,and every time you have a new material it's like a new chessboard for these rules to play out 
[Yes but chess squares would have nothing to do with anything unless you knew what the hell was going on in theoretical physics - which is why I keep mentioning chess squares and everyone thinks I'm mad -LB]

that's a major challenge,and the answer....sorry..

Quentin Cooper : Isn't it like the phenomena of the receding horizon? You look like you're a couple of miles away - and then when you go those couple of miles,you suddenly see,oh actually from here,it's another couple of miles but.....you've covered a lot of ground but every time you get to that new place,you realise how much further you've got to go?

Andy Schofield :   To some extent that's true,but also materials are developing at the same time so they're giving us new ground. So every time a materials scientists comes up with a new material,as I say,those same rules are playing out in a different environment,so it is genuinely new questions that are emerging.

Quentin Cooper :  Okay I'll spin from the negative to the positive here. So let's be optimistic here Russell,let's say you do overcome these technicalities and we are there and however many years is is down the line,we do have these magnetic computers,are they going to look the same? Is it just going to be the internal gubbins that are all different? Or are they some entirely different beast that we can't even speculate about yet?

[see members.fortunecity.com/templarser/qcomp1.html & qcomp2.html]

Russell Coburn :    I think that one of the things that we'll find is that you'll be able to put computers in places that you haven't dreamt of putting them before. So I think probably number of them won't look like computers,because there will be no equivalent. One of the promises or one of the dreams of magnetic nanotechnology is that it will give us very cheap computers,probably not very powerful,things that can do fairly basic functions,but that you can make for a few pence,and which use tiny amounts of power.

Quentin Cooper :  Oh right and because of the cost that allows you to open up possibilities that you'd never dream of doing for your £1000 PC?

Russell Coburn :     Absolutely.

Quentin Cooper :  So you have computerised cuff-links or whatever it might be.  

Russell Coburn :   That's right,or one of the ones that I'm quite excited about is we'll probably see active paper coming soon,where the computer screen is made just like a  piece of paper,now if we could make very intelligent chips that are very cheap,we could actually incorporate one of those chips into the active paper as well and we could have smart paper.

Quentin Cooper :  So it's not just the computer that's going to be changed by this,it's just the very idea of what we process and how we able to process, the scale on which we're able to process,and most importantly perhaps the cost at which we can afford it,so information becomes a much more fluidly,freely available commodity?

Russell Coburn :   If you look at the way the working world,and the way leisure and the internet have changed since the days of those very early IBM mainframes - that came about largely because of the low cost PC. If we could go down another couple of orders of magnitude again in terms of cost and simplicity,then I think we'll see an equally large change.

Quentin Cooper :  And a couple of other nanomagnet applications you can come up with beyond computers?

Russell Coburn :    Well I think one of the..our long term dream is we'd like to actually see if we can  implant some of these chips into the human body. Again if you want to do that you have to make them very cheaply,and you have to have a way of getting power to them. The problem of putting a chip in the body at the moment is that the batteries run out and you have to have an operation to change the batteries.

[Why not have chloroplasts at the surface of the skin and/or use solar power -there are types of plastics now that semiconduct - it's possible to make skin which would make electricity to power things or even convey light direct to the chips and possibly exploit that - LB]

But I'm sure there are a number of medical conditions where people can lead a perfectly normal life,as long as a certain body function,be it blood sugar level or blood pressure is continually monitored,and some sort of warning is give to the person if something has gone wrong,now to do that we need to put some form of processing under the skin,and this maybe a way to do that.

Quentin Cooper :   It'll help Kevin Warwick finally fulfil his dream of becoming a cyborg! And Andy what about spins wider applications? Is understanding the twists and turns of the electron..it's got more importance than in terms of getting better computers hasn't it?

Andy Schofield :   Yes,I think it's a big area,and also being able to control what a spin is doing at an atomic level is going to be a key - not just applications - but perhaps to what theoretical physics and condensed matter is going to be doing for the next few years. So I think the more understanding we have,more applications will then flow out of that.

Quentin Cooper :   And finally,any ideas Russell..can you give us some sort of time frame for all this,if indeed Moore's law is going to possibly run out of steam in ten years time,is this stuff going to be online and we're smoothly going to make the transition?

Russell Coburn :  I think it will be very smooth.People like IBM and Motorola,they plan to launch a chip with magnetic components for memory in 2003,so next year. My own group are working with some business people to try to bring a smart card out in a similar time frame.

Quentin Cooper :   Okay well thank you very much Russell Coburn and Professor Andrew Schofield thanks. Spin and substance together,let's see if they can manage that on PM! Next week we set sail for soil and dig deep to unearth the complex story of the millions of bacteria,thousands of protozoa and hundreds of fungal hyphe and other miscellaneous creatures you'll find in a single cubic centimetre of common soil.