All right. So I'm really happy to to start this Friday's colloquium and really happy to
also welcome shop on shop at apartheid sorry mispronounced shop on has really
great and long history of achievements and contribution to accelerate the
science as you of course know now shop owner is visiting professor in Oxford,
but through his career he was working at CERN and he was contributing to develop a collection called In the Work in these Nobel laureates,
Vandermeer and Rubins. And he was working in in the US when he was developing various ideas for superb factory development.
The various ideas and the feedback then bawtry after didn't believe them first and many, many other things.
And today Chopin is going to talk about parallel will be my guest so keep your
people tell us so please you spend to the avenue to yes it was our effort.
Okay. Right to sleep.
Girl. Yeah. You hear me? Right.
Right. This past weekend. Competitive fighting over there.
Thank you very much for for the introduction, Andre.
So I want to, first of all, thank you. Very bad optics. I have to go this here.
First of all, let me thank the Oxford Mathematics, Physical and Life Sciences Division for giving me this long term visiting appointment at Oxford.
I want to thank John Wheeler. Hopefully he will show up and have my talk with the head of the physics department.
Ian Gipsy Particle Physics and of course, Andre, my colleague from John Adams.
I always forget giving credit to people who actually informed me of institutional information from various places.
So before I forget it, at the end of my talk,
I wanted to just to try to see our friends around the world have given me information about what's going on in their labs.
So I would just say a little bit about beings and why it is such a powerful instrument for
science in terms of it carries energy and packs information and directs it the way we want it.
To talk a little bit about that mentioned the connection of acceleration and radiation
and the intricate fashion and periodicity of structures in that connection.
Particle physics explores the energy aspect of these beams very effectively,
whereas photon sciences and neutron sciences and all other things that actually exploit the information content of it quite, quite effectively.
Talk a little bit about superconductivity, which is beginning to be more and more important for our field.
I give you a little movie of how to the free electron.
There's a work generates coherence out of randomness.
You know, pretty much the entropy increases by design.
And if I wrote equations, that would be too complicated. So I have a little movie to show you.
And then I talk about why we pay a lot of attention to energetic beings and how to store energy.
We have not been very good in our field on how to make very good beams,
meaning ordered beam that can store a lot of good information, very cold, coherent, degenerate beam.
If you can do that, you can actually save a lot of money by having a compact system that does not require very large infrastructure.
And so at the end of my 40 year career, I'm focusing more on how can we produce much colder beams than more energetic means.
Okay, so if you look at the dictionary, sorry, I'm in Oxford, but I have to give an American dictionary here.
If you look at the you see the definition of a beam, all kinds of definitions, including bodily definitions.
Exactly, says a ray of particles.
Fewer particles are binary like x rays.
And actually, most of the time these guys are producing accelerators.
So what I really talk about Beam basically talking about directed flow of energy and information.
And this energy can be carried by particles, charged particles, photons, light, and it can have different constituents in a sort of inside it.
And because it can also paint the internal degrees of freedom of this beam differently,
it also carries you can embed information in and I saw that you have this and you can direct it.
Then it becomes a tool. And of course, tools have been we are humans, we have been using sticks and stones and tools.
So this gentleman said many,
many years ago how good an instrument is the not intensely advanced knowledge of much of the application of a new instrument so beams
under control situation under human control can be exploited to give to probe various things and hence the diversity of beams use.
Okay, now the energy of the beams is simple.
You can either count the electromagnetic energy storing the beams of light beam, or you can count number of particles.
They are momenta and stuff and add up and you get some kind of stored energy.
And if you look at details into the internal degrees of freedom on the beam, it has a certain amount of information.
And of course, particle physics uses the quantum subatomic information, but it has a classical information content.
The statistical mechanically, you can define an entropy of a beam of some distribution in its phase speed,
and you can actually mathematically define this object, which is the information content in the beam.
And we have not been able to use that part, which is what I talk about later today.
If you look at it, just light beam and it's just to be provocative.
Either like beam being shown for the Livermore Valley in California looks very benign, but the inside is a very complicated phase based structure.
And we've come to a particle beam. Which you are directing and focusing.
If you look in the details of this General Dynamics, you are confining the beam under nonlinear forces that are very many linear
and nonlinear resonances that make the internal motion extremely complicated,
she lamented. And sometimes it goes unstable, sometimes it becomes stable.
And these are actually the continual problems that particle accelerator designers are
struggling with when the design language machines now come back to particle physics.
And also particle physics, of course, uses energy, brute force collide particles of opposite energy,
and you generate fireball and you can produce various quantum numbers coming out of the general energy ball.
And typically that's the aspect that we have used very well so far.
And if you look at after the history, this kind of a collider,
we try to answer all kinds of questions by generating untainted energy in the centre of mass,
which is free, which is just to crystallise into very many manifestations of the particle zoo.
And so there are many, many questions we have.
And actually all of these nearly all of these require either extremely high energy accelerators like we talk in our TV class, particle colliders now,
or very high intensity accelerators like proton machines that producing neutrinos that
you could do very precise determination of the of the parameters of of those particles.
And historically, I have to tell you that starting from where I was pedigreed in Berkeley for one metre all the way to there,
you're talking about 100 kilometre colliders. We have a 27 kilometre collider.
We just discovered the Higgs was on a couple of years ago.
So this is where we have come. All this distance is getting bigger and bigger and larger and larger, of course.
And if you look at the comparison of this, it's a cyclotron 1930s and 80 years later we have 27 more energy density,
five larger that actually scales with more favourably.
The cost doesn't that I'm not going to talk about the cost, but of course this has discovered something for us, right?
So we know that we have together with cosmology,
I have to say that all the time I'm here is not just particle accelerators, cosmologist astrophysicists,
together with them, going back in time to the beginnings when the big bang core gluon soup are beginning to crystallise into ordinary matter.
There's still a lot of mystery here. We are still not deep into it.
It barely comes close to inflationary scenario.
They do not know where the dimensions disappeared.
Matter seems to be at a dark sector to matter. There seem to be an invisible type of energy for dark energy and all of that.
So after all these hard work, the ordinary matter, hydraulic matter,
the matter that is our stuff is made up of stars, the sun, the galaxies and interstellar matter.
That's only 4% of the universe. But the accelerators are given the handle and continue to give a handle on those 4%.
So this was a couple of years achievement last two years and actually to the future.
Now people are talking about very, very large accelerator, 100 TV, proton and proton and the Geneva site.
To do this, you need very strong electromagnetic in a magnetic field for 15 to 20 Tesla.
And this is where I was telling my friends at Maxwell and Neutron fight because it's
not enough to discover or invent a new superconductor that give you a very high field.
You also have to have a mechanical structure that can sustain the Lorentz forces that comes out, that wants to break it apart.
Right? So that's one axis. The other axis is actually producing superconducting electro magnetic traps are cavities
that have travelling waves or standing wave that can go through these fractures,
which can accelerate charged particles very, very efficiently at reasonably high gradient of tiny deforming 40 megawatt parameter.
So these are the two large high energy activities that are on the horizon.
None of them are done. These people are designing. It is a very mature situation, but costs and scales are prohibitive.
I'm not so sure about the reality of international linear collider.
This BP 100 TV beginning to be thought about and and in any case,
it is so big it probably would be an international affair, not just a European facility.
Now back home, where I am now, in Fermilab, another axis which is now.
Is the neutrinos and neutrinos. They're very ill understood objects like Kabuki, they change the character of the travel.
There's a ambiguity about the masses and mixing of different types of neutrinos.
So there is, again, high energy and high intensity accelerators at Fermilab directing the produce neutrinos
from the proton complex very far like 800 miles to the underground laboratory.
And so the idea is to make a deep underground nutrient statement, which is supported by a very high intensity accelerator from that.
And that is the neutrino frontier that's driven by accelerators.
In parallel, there is an effort in Japan where you get the neutrinos combination of the active neutrinos and also high current proton machines.
Okay. So of course, this collaboration is a life particle physics at Oxford is a large group and so a very, very large collaboration.
And naturally, you lose your identity in a big team unless you have discovered something very quickly and very visibly.
So these are very large experiments. Okay, now I want to do tiny little bits that every time you have an accelerator you also have a radiator.
And you see that because if you look at going very far right, you know, you see beautiful radiation coming out of the cannibalised.
It's actually charged particles being going around in motions in very strong electromagnetic field in the nebulae.
And they seem to turn radiation in in the earth.
In a lab frame, you see a little butterfly and actually you can see a diffraction pattern of the ring.
You see carefully your periodic structure there. And every time you want to accelerate a charged particle,
you have to make sure that that particle is also allowed to radiate into the same mode that you
want to use to accelerate if is forbidden for the charged particle do to radiate into a structure,
you can never use that structure to accelerate, and that's the fundamental things about it.
So this connection is also problematic because all the problems of these high energy
colliders come from this beautiful radiation that you get out of our particles.
I mean, you can harness that radiation like in light sources.
People do it. But in the collision, it causes problems because it's a very intense radiation.
And so most of the R&D on these very high energy colliders is naturally on the magnets,
which are bending these particles to very sharp magnetic fields.
And they have to be tolerant. The vacuum has to be tolerant of this high radiation and the radiofrequency cavity has
to supply the energy that you are losing into this extremely high radiative and ground.
For most of the research, for these high energy colliders,
either the magnets or the cavities or the environment of the beam radiation system, you have stability and control of the situation.
Yeah. So if you look at, for example, these colliders I just talked about,
you have a lot of research on new types of materials that can produce 16 Tesla magnetic field,
electromagnetic and electromechanical design or you look at RF cavity that can support very high electromagnetic field,
an exploding field in niobium efficiency of transfer of energy and so on.
So for this is completely engineering and technology driven focus.
And then of course you have to look into the dynamical aspects of charged particles being that has to experience all these forces.
So whether it is a large ring like LHC or a linear accelerator or some of these plasma accelerators people are considering today.
We are just trying to produce periodic structures that can actually allow it to radiate and at the same time accelerate.
And if we look at it, if we just were not concerned with intensity, just with single particle, if we want to go to very, very high energies,
of course, as you go down in size, your frequencies of structures go very high and they can then support very high electromagnetic field.
And so people are going from large gigahertz type structures to smaller and smaller
structures and eventually plasma where the wavelength is micron type wavelength in a medium.
And and so this is the way the high gradient acceleration part is going as a single particle is concerned.
You still probably cannot support a very high current in this type of accelerators.
Okay. Now, let me just the main thesis of my talk is that we have not learned much about how to harness the intrinsic order of the beam,
which is very important, and actually synchrotron radiation.
People are actually using it very effectively, but still not as effectively as we could offer them probably.
So I gave it to examples. One of the very large linear superconducting not being constructed at Stanford in California,
we have X-ray free electron laser and I don't know what is a daisy again, very long 14, 15, giga volt.
You get that from the linear accelerator being built in Hamburg and these are actually based on superconductivity,
the key element of it and this mechanism of how do you generate order motion out of totally random thermal b are you coax order out of randomness?
And these are the two tricks that are at the bit of the at the foundation of the field.
So let me take a little bit of detail now into the internal degrees of freedom order of the beam.
So I told you that there is this order and you can paint it in a way.
And this order is actually very dynamic quantity and is constantly is very restless being in the in the face of the beam now.
And if you think about it, long time ago in the 1830s, this gentleman, Frenchman,
thought of internal motion as a very smooth, slow guys, leaving the inflow of a fluid in space.
He did not like very many disturbances and he doesn't like a smooth flow.
And so if you do not have any losses, it's a not a dissipative system, not much friction,
then everything should be smooth and continuous and you have so-called nouvelle theorem that you can deform it gently,
but you cannot really squeeze it expanded. You did it in 1837.
Next year he corrected himself, saying, Oh, that's not true. If you have non-conservative dissipative force and then you can treat rock.
Now, 50 years later, this gentleman Poincaré to him first space.
You do not have a flows and stuff. It was a totally geometric structure, all kinds of fixed points and unstable fixed points apparatuses.
You have elliptical fixed point, hyperbolic fixed point,
and you are studying the intrinsic randomness of the dynamics coming from very small uncertainties
in the initial conditions of the particles will lead to in a finite length of time,
totally unpredictable trajectories. And that's the kind of randomness intrinsic because you cannot make initial conditions infinitely knowable.
And so he did. In a way, these are nonlinear dynamical systems which are kind of unstable because you cannot control the initial conditions that.
Well, and then came Mr. Random, who had the good fortune to work with, who actually looked at phase space,
very hybrid electrical engineer engineering may very, very grainy and lumpy.
It had a flow in it. It also has a lot of empty space.
And I can invent an electronic Maxwell's demon, which can look into the holes in the phase space and compact inside the phase space by itself.
And he introduced an electronic Maxwell's demon that could shrink the face of the beam by this electronic thing,
which makes it appears like he was violated. You are actually changing the controversial law of evil, and that's not true.
Actually, this was predicted by this Chinese scholar. He was saying that, you know, if you if you consider a real which is poked,
you have to make a hole in the middle to make it useful because all the spokes have to come in the middle in a circle that makes it go.
If you do not have the hole, it is useless. Just to have substance without void is not useful for faith.
Space is extremely useful because you have granularity and fluctuations.
It is not completely dense and full. You cannot do anything with it.
So there are just fluctuations and if you have a way to measure it, you can then make something out of it.
And that was the whole idea about this. So the more compact you find this faith space is, of course, the more order there is.
The entropy goes up and you have to do something. You have to take heat from the system deposited elsewhere and cool down the beam.
And this is where the problem comes in, because the charged particle beings have to start somewhere,
either from a gun, from a cathode where you simply heat up the surface.
And the thermodynamic for work function of the metal is a potential barrier that the charge has declined.
And that's because it comes out of the metal into the baggage, which is a potential energy, which immediately translates into kinetic energy.
So it is very restless, you know, the temperature. Similarly, when you have for the cathode semiconductor surface, you shine light again.
The atoms are band gaps and the electrons are to climb.
The bandgap out of the semiconductor is an advantage. But yes, I climbed uphill and all I can be free for.
You had all that restlessness in it.
So typically I'm not very proud to say this today charged particle beam that from being as hot as the surface of the sun,
the thousands of degrees, heart and nothing does.
And if you could fairly make them hundred Kelvin or one Kelvin ordered being called electron beam, things could be different.
All right. So now after that day, let me just tell you now, how does the guy, the Stanford and Humble,
trying to coax order out of a very random restless electron beam.
It take the many, many kilometres to do it expensive technique because the beams are crappy to start with and not good enough to start.
So here, I don't want to insult anybody's intelligence. I show you a little thing about superconductivity.
You all know about it. I know it's in physics here, but if it invented 100 years, more than a hundred years ago,
when this gentleman discovered mercury loses a lot of resistance at a certain temperature, and that was a part of the working activity law.
We utilise this in cavities in two ways.
One, if you just have a cavity wall trap energy, if this cavity is not ordinary metal like copper or aluminium, the energy started back and forth.
It heats up the wall and then you have to stop because it gets too hot.
It's even getting it will get red to stop.
You have to stop. So you have to repulsed operation.
And we try to pack as much energy into this process.
And in the past when you have to do it, it means there are issues, the pulsed energy and that's not easily controllable.
If you go to superconducting because you have lots of resistance,
energy stored can start rattling for for microscopically long enough time that you can fill a large number of batons with small intensity.
They can control it and do it much more precise in the control of the beam.
And that's where the superconductivity comes from and is useful as well for today's accelerators.
Okay, okay. So let's see how it works.
So we are showing a movie where you have a laser beam coming into a four into a metal for two cathode electrons are coming out and that's
where all the badness starts because the electrons are very hot and immediately captured by the accelerator and taken to very high energies.
And then you try to coax order out of it instead of writing Maxwell's equations and stuff.
I'm going to show you a movie and please don't be insulted.
This is niobium, which is superconducting at two degree kelvin, which can hold a lot of energy inside.
And you build them with special purpose, very precise manufacturing tolerances.
You build a large number of this cavity, the projectors surround them,
so it's cryogenically isolated and you collect a whole number of them and make an entire module.
And this module is called the Cradle Module. And typically one of these RF modules gives you 100, 200, 300 megawatt of energy.
And so that's the Crown module. Yeah. And May.
Many of these to get to high energy. 100, 200, 300, 400.
And so on. Are you have to inject the particle somewhere.
Here is your surface light beam comes in photoelectric effect or in this is where the battery that
you injecting a bunch of particles which are being focussed and accelerated by this structure.
Now whatever you do with this beam, eventually it cannot be any better than what it was born with.
We are good at messing it up. It is not so easy to cool it in just a length of 2 to 3 kilometres to make it better so it simply can get only worse.
So if you start with good enough beam, that is one thing.
But if you start with such a hard beam, you can only do so much with it.
And that is that the basis of why our activities are so expensive today and they are costly
because we have to do a lot to them to keep them ordered and simple and still be useful.
So you get it, be very familiar, do something with it, right?
And so what these guys do in the Freedom Collider community is that they take these charges that are coming up and,
you know, a charge is nothing but trap light, the virtual light trapped in it.
And if you manage to shake it hard enough by magnetic field, that light would peel off from the charge.
And in 1940, before QED, while Discovery was called Virtual, why is Dr. Williams quanta anomaly?
You call it. So that's what they tried to do. And in the process of shaking it,
you have to generate some kind of order in the beam every time you shake a
particle because alpha a fine structure constant in this one number one over 137.
So you have to kind of shake it 137 times to get one photon out.
How quickly you shake it tells you what the colour of the light that you get, how hard you shake.
It will tell you the intensity of the light that you will get.
And it is a hard process.
And here after when you do it sufficient number of times, initially one or two or three particles of light is purely non-classical.
You cannot define the electromagnetic field. Coming from just one or two photons is very difficult.
But once you have gathered a macroscopic number of 10,000, 2000, 10,000,
it creates a electromagnetic field pattern which react from a charged particles in bunches which give them competitive fire,
which then enhances that emission and that emission and bunches of particles even more.
It becomes a positive feedback loop which grows and grows and grows and saturates.
So the equations are complicated, but let me just show you the movie.
So here you see magnetic device where you have north and south poles.
And from a distance you see this I got from my friend from Daisy Head who are building their field.
You see this electron beam coming and being shaken madly so you can shake up the light out
of this and you see light travels faster than charged particle with the charged particles.
Current speed cannot beat speed of light. This is a plume of light in front of you grow, grow, grows dry.
And when all the light is out, way to take it out.
If you have the right now, if you look in slow motion inside the dynamics of the beam, you see that this is guy slowly oscillating.
Every now and then you get a little light particle, which is you will see that would be a little step.
This is all electrons. Pretty soon there be one or two or three light particles that go.
This is hardly doing anything. But when you have large number of them, they create an electromagnetic field which bunches the particles.
You see now these creations in the beam which generates more light, a bunch of them even more and more light is a positive feedback.
And then the light becomes ordered by this self amplified noise it saturates and then
extracted because there's nothing more to get from this charged particle anymore.
So you actually start it all with a very random beam terminal at a temperature of thousand degrees Kelvin or more.
And you shook it and shook it and shook it and let the light coming from the seed noise schottky noise from the beam.
You let it interact with the beam in a clever way through a bunch of the beam and slowly brings order into the very, very hot electrons.
So this is a mechanism of self amplified spontaneous emission, right?
And that is the basis of the if you are at Slack, Stanford and at Humboldt in Germany, okay.
By this alone, it takes kilometres. We accelerate and it takes long on generators to coax this order out of the wind.
It's an expensive proposition. And can we do better?
Can we actually tame a particle beam just like dim light be light beams, lasers compare.
Can you do a particle beam as an effort and the reward of what?
If you could do it? If really? Very nicely. All right, so now I'll give you some numbers.
The temperature scale, you know that people are doing atomic physics experiments.
The atoms are kept in traps and lasers, and they get very, very cold temperatures on a single molecule or single atom.
So they hardly call it a temperature molecule when nano kelvin, three degree never comes in.
And there is no fundamental limit to how cold you can get a single atom.
It's a big object. And yet we have not been able to produce a single free charge,
a proton or the electron or any other charge to be that cool and to be extremely difficult and mean.
And most of the reason why, as soon as you disturb is charged particles, it emits some kind of radiation which a neutral particle does not.
And the best you can do is to resolve the charge at the same wavelength that the charge emits light, and you can't do any better.
And that's one of the problems with it.
So if you look at a typical if there are any after a physicist, if you want the density and temperature, they just line I drew,
which is when the collecting energy is more than the internal potential energy of the Coulomb below this line are very dense,
degenerate, strongly coupled plasmas.
And above this line, they're all weakly being is sitting here very tenuous, very dilute and extremely hot.
It is just not a very impressive object in this diagram.
Our goal is if we are to pull this guy down this direction, get it colder and get it denser below this line, and then you have a degenerate being.
But then quantum mechanics begins to interfere. I'll tell you about that.
Okay. So how do we. Okay, so just just for the sake of an exercise, if instead of the thought that hot beam,
if a similar to the one degree Kelvin beam and very few particles tend to the 6 million charges.
It's not that big a number rather short balls,
but you have a very cold beam and you see just with a laser or with some kind of a terahertz source and you get just a 6.5 of electron beam,
you do not need a 18 GB electron beam. You already get K.V. X-rays because again,
length is very short and you can actually get a tabletop coherent X-ray if you if the beam could be made this small.
Okay. So that's that's the attraction of it. And we have to learn how to do this.
And we have not put enough R&D effort into that direction in our field.
So I think that's for state of the art.
You put a lot of particles and do light into the 11 nano coulomb of charge.
Everything is okay.
But this number, which is the temperature of the beam, has to be reduced by 100,000 and that has to get much, much colder electron beam.
And if you look at it carefully, the light that you get is just a mapping from the particle beam and vice versa.
So in the fundamental moment, the Gaussian beam, you are collapsing.
It, it diverges, it refracts. Similarly, a particle beam can be squeezed and you go from the you can map one to the other.
The whole idea is to map the faceplate of the tube as tightly as you can so that there is no inefficiency between the two.
And this is where I want to show you a little bit of a concept of coherence.
If you look at a charged particle, beam is rather big. And if we deal with microwaves, which are rather big, also gigahertz type, centimetre scale.
And if you look at a laser beam, which is much smaller, and if inside the charged particle beam,
there are many, many little, little volumes of coherent information that is generated by the light beam.
Okay. So you actually have a mismatch between the intrinsic coherence volume of a particle beam and a light.
And this is where most of the loss is taking place in terms of getting order out of chaos or randomness.
Okay. So people can do mathematical, very fancy statistical mechanics of this.
Define degeneracy parameter. You define fundamental phase space of the particle being under control is the best you can do in terms of
diffraction of over matter wave that you can resolve and you can see how many of these cells are inside.
So you can define it typically in nanometres.
A 30 nanometre type of a charge particle source.
You can think of it as a millimetre source with a micro radius divergence.
You know, things like that that have a temperature quite small and it gives you a quite coherent being.
So this degeneracy parameter is quite small. And so if I give you some numbers inside of it, you'll see if you look at light, which is a spin,
one particle in a high power laser lasers, you have another for light, for example, you have a large number of photons inside of pulse.
And so it's a very classical light, very coherent. On the other hand, if you take blackbody radiation, it's very incoherent, very fluctuating light.
And we need quantum mechanics to describe it in between.
In the diamond light source, for example, we are sort of like a hybrid beam, which is partly coherent, partly incoherent and so on.
Knowing that that light into an electron is charged from your own system.
Yeah, the best you can do if you are not very social being, they don't like to sit together.
They're not to share their napkins. I'll let the other two different coloured napkins been up and down.
Okay. You can sit. Otherwise you have to sit at a different table so they don't like that.
They are not very degenerate by nature.
Best you can do with two typical electrons.
Follow gum for a third to have ten -11 degeneracy.
But I want to go to 20 minus six. We have to limit a little bit of order out of this Fermi Gas system.
So these are the typical numbers that that you talk about. Yeah.
So what is the best one can do?
And again, without giving you the mathematics, you can actually write down the best you can do with this with an electron beam,
which is given in terms of the fundamental number like charge of the electron speed of light,
quantum wavelength of the particle, and this degeneracy parameter.
And then a little number, which is a voltage of the potential that these charges are to go over.
Now, this has to be very, very small. Otherwise you do not get a very degenerate beam.
And if you look at the state of the art, most of them are very hard beams,
except you are hitting the quantum limit only when you go to special types of surfaces like nanotubes,
field emission, carbon nanotubes, metallic tips and maybe plasmonic cathode together to go to the quantum limit for the ultra v the critical number.
So you do not want it to be the work function of the metal. You do not want it to be a quantum world you want to tunnel through.
And so the tunnelling is provided by the field emission Nanostructured Photocatalyst okay.
So you can either make a very finely structured cathode,
but you fail to distort the potential so that charged in the quantum mechanical tunnel salt and return inside it does
not feel the weight of the baggage really never have to climb anything and simply tunnel through the very cold still.
Or you have to think very clever way of doing plasma physics.
You have to take a beam which is not coming from a metal, is not tunnelling, but it is an atom where the electrons are a very high quantum number.
So the kinetic and potential energy cancels out and they are almost ionised.
So they are pretty much in the close to the continuum and these are called atoms and they make a little cathode in a plasma,
which is a red box state, a little hole, and they extract the electrons out of the plasma, another degenerate electron beam.
They're very complicated technologies to do these things, but that's why we have to go to make very clear from beams.
So there's some work being done actually around the world.
I mean, we are doing some in the States, did some work in Cambridge, did some work in Eindhoven.
Philips is interested in very cold cathode, not for our applications, but for flat panel display.
Graphene is a new substance, so people are exploring graphene, so nanotubes are graphene sheets anyway wrapped up.
We know how to produce these things and some people are working on plasmonic catalysts and stuff.
And actually there is hope that with a lot more advancement in materials science,
probably one can get a cold enough cathode to go down to 110 degree cousin electron beam temperature.
So the today's best candidates are these cold field emitters coming from nanotubes.
But nobody has explored the plasmonic cathodes yet, which would actually give you a much better order in the technology side.
So of course mathematics is important. You have to design this and then the whole subject of computational.
Nanotechnology at our does really folks at the and this Andrew maybe they're they should be working on this issue
of how to generate special materials with very good filtration properties and a lot of computation goes into it.
You cannot just take by trial and error. And so this is a very interesting field.
So I think in order to make progress in particle accelerators, we make very, very cold beings.
We have to embrace these nanostructures and try to attack it at the source and not try to cool the beam onto it produced very badly.
Okay. What is the ultimate limit?
Even if we are a single electron, let's say you got know just a single electron can make a single electron have a zero temperature, huh.
So probably not because you can look a single electron and you try to focus it.
We want to make it come to sudden focus. We use a perfect lens, but if it has a little temperature, little divergence,
then you have some kind of a spherical aberration is dependent on the momentum,
so you have some kind of romantic aberration and then of course material defects, quantum mechanically.
So ideally you get a root mean square has the resolution of this electron beam and if you do this, you get actually some minimum,
minimum achievable quantum mechanical, limited temperature or resolution of the electron beam, but not quite.
You do not quite reach that limit, mainly because as soon as you try to bring it down to that resolution, you start to emit radiation.
And finally you find out if you do the thinking right and the calculation right there,
the fundamental volume of the electron limited to the wavelength of light that it emits.
And you can never stop the charged particle not emitting radiation.
It's always emitting radiation or photon short remnant alone.
If anything long of that, you don't know where the electron is. If everything short of, then you can probably get very short dimensions.
Okay, so this is the whole problem that we are talking about, very, very cold electrons, very, very few particles of light.
And I said that the alpha being a small number, even if you have 100 photons in the sample, 100 electrons in the sample, which is very, very cold.
You're talking about one particle of light and one particle alloy, which is always there from the amplifier.
So the quantum optics of light, even though your your charge to be an electron is classical, you know, the classical order.
But when you map it into a photon field,
it becomes quantum mechanical by just very nature are dealing with very small number of photons which are always fluctuating.
So this aspect of charged particles, we have a lot of I'm just trying to point out point out to you, okay, if you could actually do this,
you can actually see you can see this light in this little pulse of light and you can actually play around with these pulses.
You can begin to have colliding pulses of wave functions of just light field from from charged particles.
You can see quantum mechanical wavefunction collapse. You know,
people are doing atomic physics experiments where the shine very short pulse
of X-rays and they do not ionised atom incoherently like 1 to 3 electrons.
You know, they actually excite the entire electron cloud,
which is correlated with quantum mechanically in the field of nucleus, but they try to peel off from the nucleus coherently.
The square observation you try to do the same thing with the charged particle, try to separate the light field from the charge.
And in the most difficult experiment,
the charge gives out light to charge has no identity and a charge so you can do all these fundamental experiments.
It's very, very cold electron means that has not been possible so far.
So some small fraction of the electrical beginning to look into these problems that that forget about bound systems of atoms and molecules
can really understand the quantum entanglement and this entanglement of a single charge emitting radiation in the electromagnetic field.
Okay. And I just want to wrap up because it's getting late so you can then devise all kinds of interesting experiments with classical systems,
and you can collide lights with particles, you can collide multiple pulses of light with particles.
And see, I'm just it's just a cartoon to show you.
Compact laboratories can set up their own input in a university and have multiple physicists and stuff.
Academic studies. No one can one can design colliding pulses of quantum mechanical single electron colliding with a single pulse of light.
Coming from another electron and so on. Control experiments.
One needs to have a very compact trap for a single charge particle, which we are trying to build at Fermilab, actually.
So just to stimulate your interest in the subject.
Okay. Let me just go on here that if you could and I have been thinking about this for quite some time,
if you could have very cold electrons, you actually do not need x rays or light to interrogate the engine of life, which is protein.
You can actually interrogate and initiate some kind of coiling in a single strand of protein molecule,
which when you pull it apart is about a metre long,
but quickly you go down into a coil state and in the process it goes through several configuration changes.
You can actually send very special pulses of light. Single electron, double electron.
And the radiation that comes with it and actually can probe the correlation in this trend as a function of time.
After all, folding is nothing but a correlation of this string at different times, at different spaces,
and in the for your transform in the double for you want to have this number evaluated as the protein folds dynamically and you
want to do it in real time and the time resolved spectroscopy of a folding protein with very little perturbation on the string,
either by its very short pulse of a very short charge.
And that should be possible if we could get such called electrons.
Okay. All right. Well, I'll just have a little bit.
I got this request from my friend who's Contently, who says that we are too simplistic in our understanding of correlations and charged by the system.
That's why we are not making progress. If you look at superconductivity, if actually you have a bunch of electrons, okay,
and if you have some impurity of it, electrons scatters off from it and it gives rise to resistance.
Yeah, that's because the electrons are acting not in in phase, but in coherently.
But if you make them to go in lockstep, like their phases all coupled,
they ignore the impurity and you can actually make it go through actually the
way you can understand superconductivity as superfluidity of charge for that.
So that's what I just showed you, that when the electrons are correlated, they're little.
Macroscopic numbers don't matter, they ignore it and they are coherent flow.
So in a similar way, we are used to correlations in pairwise fashion most of the times.
And like a classical dance of dance between humans, you can define two or three species of gender.
I don't care, but they are still correlated according to that, right?
You do this Cooper pairs or Adam pairs or colloquially that problem.
But problem comes naturally when you have a much more complicated underlying dynamics and you do not have equal species.
What if you have more men on the floor?
What do you do? Do you actually allow the men to stop the dance?
Let me see your question. Time and or pattern and system.
You just go, that's not good, right? Do you want them to just leave the floor so that you feel an equal number of men and women?
And then we have separated the phase of the thing and you are not really acting together.
I did actually invent a new kind of a dance, actually, that does not have to be for very high in order correlation that still allows you
to preserve some kind of a concerted dynamics and with nontrivial correlations.
And that's actually what when you look at the Fermi Gas of electrons of charges,
you have to invent that kind of a correlation and then try to do so after modern dance.
All right. I wanted to show you something that people I was fortunate to have taken class from Mr. Bose before he passed away in 1972.
He passed away in 74. And he actually told me how he came up with the plans.
BLACKBODY And it is the formula that people were delighted with teaching.
People were deriving, uh, when they talk about energy, they were staccato fashion, quantum plants, age ma omega multiples.
But when they're calculating moles in the cavity, there are continual waves and you count normal modes in the cavity.
And he thought there is something wrong with it. Either do all modes or do all particles.
Quantised and as a result the radiation could not be derived appropriately.
He assumed. What the heck, I do not care mathematician. I'm going to assume everything is quantised, including momentum and phase space.
And then quickly within a few steps he got the BlackBerry thing and he got it because he and he was a musician.
He used to play. An instrument called this rod, which is although it string and has frets and it played continuously as opposed to violin.
So I'm going to play a couple of pieces.
One of the violins is not played by time, and one is a piece on this instrument not played by Bose, but he composed it.
His favourite a flute. This is a western violin.
So you can feel the digitised music there. You can hear it in America's digitised truth if you look at Mr. Moses.
It's large. And this is a normal motion box for the raves going on in Quantised.
And if you've seen this composition of somebody else's playing it, of course.
Well. If working really hard, you have to be patient with Eastern music.
Right. You are very aware of this difference of modality from the two or the normal mode one
is and that's trying to come up with this both tentative dates and he said I don't
care whether these are real particles and marvel give me plans long in the three that
might be true turned out to anyway so let me just go on now I finish I finish up.
Well, can you really produce quantum degenerate electron beams?
I do not know.
There comes a point in time in your career where nine out of ten things you were asking for and I can't be done because I have looked at it.
I've thought about it. When that one comes, I think I'll fold and I'll just stop doing research.
But it has not come to me yet. I think there are ways of getting there very close to it.
But you have to just have from imagination, knowledge, the enemy.
At this point we know too much about quantum mechanics and stuff.
We were tempted to say it's probably not going to be possible, but we have to just abandon it and just think carefully about it.
And that I Frankenstein, the end of a 40 year career high energy particle, left letters and stuff that's going on.
I'm still contributing to it, but this is something that probably more young students,
companies like Oxford and stuff should pay attention to become fantastic.
If somebody can do this. Got Nobel Prize one degree Kelvin free.
Let's do it. Thank you.