Beyond Bosons and Fermions: One-Dimensional Anyons

<v Speaker 1>Welcome to the court Side Quantum Physics Podcast, an exploration
<v Speaker 1>of the fundamental structure of reality, where quantum laws govern matter, energy,
<v Speaker 1>and information. Here, uncertainty is a feature, not a flaw,
<v Speaker 1>and understanding begins at the smallest scales.
<v Speaker 2>Welcome back to the show. You know I had a
<v Speaker 2>bit of a crisis this morning.
<v Speaker 3>Oh yeah.
<v Speaker 2>I was standing in my kitchen staring at the absolute
<v Speaker 2>disaster zone. That is my junk drawer, you know.
<v Speaker 3>The one everybody has, the drawer, the graveyard of good intentions.
<v Speaker 2>Exactly, it's the drawer where logic goes to die. I
<v Speaker 2>had batteries mixed with rubber bands, a screwdriver next to
<v Speaker 2>a dried out marker, and keys to a car I
<v Speaker 2>haven't owned in five years.
<v Speaker 3>The usual suspects.
<v Speaker 2>The usual, and I decided, day is the day today
<v Speaker 2>I organize. I went out and bought these little dividers,
<v Speaker 2>one specific slot for batteries, one specific slot for writing utensils,
<v Speaker 2>one for tools.
<v Speaker 3>So you were imposing order on chaos, a very human
<v Speaker 3>thing to do.
<v Speaker 2>I was trying to. But I realized something while I
<v Speaker 2>was sorting through this mess. We as humans are obsessed
<v Speaker 2>with boxes. We have this just this biological need to
<v Speaker 2>categorize things. Is it trash for treasure? Is it edible
<v Speaker 2>or poisonous? Is it friend or foe? We just we
<v Speaker 2>have to sort.
<v Speaker 3>It's a cognitive survival mechanism. Really, our brains are processing
<v Speaker 3>millions of bits of data every single second. Right, If
<v Speaker 3>we didn't use shortcuts, if we didn't instantly file things
<v Speaker 3>into category A or category B, we'd be paralyzed. We
<v Speaker 3>just wouldn't be able to function.
<v Speaker 2>So we crave the binary.
<v Speaker 3>We crave the binary because the binary is safe, it's efficient,
<v Speaker 3>It lets us make quick decisions.
<v Speaker 2>Right, It makes the world manageable. But here's the thing
<v Speaker 2>that just absolutely blew my mind when I started reading
<v Speaker 2>the research for Today's conversation. Okay, it turns out this
<v Speaker 2>obsession with two boxes isn't just a human quirk. For
<v Speaker 2>the last hundred years, physicists have been operating under the
<v Speaker 2>assumption that the universe itself, I mean, the fundamental architecture
<v Speaker 2>of reality is obsessed with two boxes.
<v Speaker 3>You are referring to the categorization of elementary particles.
<v Speaker 2>I am. We've been told that every single particle in existence,
<v Speaker 2>from the photons hitting your retina right now to the
<v Speaker 2>electrons holding the atoms of your chair together has to
<v Speaker 2>pick a side.
<v Speaker 3>It has to declare its allegiance exactly.
<v Speaker 2>You join club A or you join Club B. There's
<v Speaker 2>no middle ground. Nope, I it's sort of in both.
<v Speaker 3>That is the standard model of quantum mechanics. We call
<v Speaker 3>it the great binary. You are either a boson or
<v Speaker 3>you are a Fermion. And up until very very recently,
<v Speaker 3>that was considered the ironclad law of the three dimensional
<v Speaker 3>world we live in.
<v Speaker 2>But today, today we are going to smash those boxes.
<v Speaker 3>We're going to see what's in between them.
<v Speaker 2>We are looking at a brand new discovery published literally yesterday,
<v Speaker 2>February third, twenty twenty six. This comes out of the
<v Speaker 2>Okinawa Institute of Science and Technology OSD and the University
<v Speaker 2>of Oklahoma, and what they have found is, well, it's wild.
<v Speaker 2>It's completely wild.
<v Speaker 3>It is a fundamental shift in perspective. It really is.
<v Speaker 2>They've found a way to break the rules. They've discovered
<v Speaker 2>a system where particles aren't just A or B, they
<v Speaker 2>can be anything, anything in between.
<v Speaker 3>We are entering the world of Enians. And this isn't
<v Speaker 3>just about finding a new particle to add to the zoo.
<v Speaker 3>You know it's not just another entry in the textbook.
<v Speaker 3>This is about challenging our very understanding of dimensional space.
<v Speaker 3>It forces us to ask are the laws of physics
<v Speaker 3>actually universal or are there just side effects of the
<v Speaker 3>fact that we happen to live in a room with
<v Speaker 3>three dimensions?
<v Speaker 2>Okay, let's unpack this. Because when I first read the
<v Speaker 2>headline a new class of strange one dimensional particles, my
<v Speaker 2>first thought was Okay, cool, another sub atomic.
<v Speaker 3>Spec Sure, that's a natural reaction.
<v Speaker 2>But as I got into the text, I realize this
<v Speaker 2>is more like finding out that gravity works backwards if
<v Speaker 2>you stand on one leg. It changes the context of
<v Speaker 2>everything we thought we knew.
<v Speaker 3>That's a fair analogy. And to really understand why this
<v Speaker 3>ois research is so groundbreaking, we have to start with
<v Speaker 3>the status quo. We have to understand the prison we've
<v Speaker 3>been living in.
<v Speaker 2>The two boxes.
<v Speaker 3>The two boxes. So let's look at our three D universe.
<v Speaker 3>Everything you can touch, see, or interact with. Every fundamental
<v Speaker 3>particle falls into one of two categories based on how
<v Speaker 3>it behaves socially.
<v Speaker 2>Socially like particle Etiquett, you're telling me particles have manners.
<v Speaker 3>In a way, Yes, a very very fundamental way, So
<v Speaker 3>let's open the first box. The bosons.
<v Speaker 2>The bosons. Okay, in my notes i wrote down the
<v Speaker 2>conformists or maybe the party animals.
<v Speaker 3>Both are very accurate. Bosons are the force carriers of
<v Speaker 3>the universe. The most famous example is the photon, the
<v Speaker 3>particle of light.
<v Speaker 1>Right.
<v Speaker 3>The defining characteristic of a boson is that it loves company.
<v Speaker 3>It is profoundly social. If you have a boson in
<v Speaker 3>a specific quantum state that means a specific energy level
<v Speaker 3>moving in a specific direction, other bosons are perfectly ha
<v Speaker 3>In fact, they prefer to join it in that exact
<v Speaker 3>same state.
<v Speaker 2>They don't mind crowding at all.
<v Speaker 3>They crave it. It's more than just not minding it.
<v Speaker 3>The probability of a new boson joining a state actually
<v Speaker 3>increases with the number of bosons already in that state.
<v Speaker 2>Oh wow, so it's like quantum peer pressure.
<v Speaker 3>It is. Hey, all the cool photons are over here.
<v Speaker 3>They pile on top of each other. Mathematically speaking, this
<v Speaker 3>is the mosh pit particle, or a choir, a perfectly
<v Speaker 3>synchronized choir. Think of a laser beam. A laser is
<v Speaker 3>only possible because photons are bosones. Well, a laser is
<v Speaker 3>just trillions upon trillions of photons, all marching in perfect lockstep.
<v Speaker 3>They have the same color, the same frequency, the same direction,
<v Speaker 3>occupying the same space at the same time. They act
<v Speaker 3>as a single coherent wave of light.
<v Speaker 2>And if they were claustrophobic, that wouldn't work. They'd all
<v Speaker 2>be pushing each other out of the way exactly.
<v Speaker 3>The beam would just diffuse and fall apart. Lasers are
<v Speaker 3>a direct macroscopic consequence of this bosonic piling on behavior.
<v Speaker 2>The source material also mentioned bos Einstein condensates. That's the
<v Speaker 2>extreme version of this, all right.
<v Speaker 3>That is the absolute extreme. If you take atoms that
<v Speaker 3>behave like bosons, certain isotopes are bosons, and you cool
<v Speaker 3>them down to your absolute zero, just a fraction of
<v Speaker 3>a degree above the coldest possible.
<v Speaker 2>Temperature, they basically stop moving.
<v Speaker 3>They slow down so much that their quantum natures overlap,
<v Speaker 3>and they stop acting like individuals entirely. They collapse into
<v Speaker 3>this single quantum state, a super atoms, so.
<v Speaker 2>You can't tell where one atom ends and the other begins.
<v Speaker 3>You can't. They lose their individual identities and behave as
<v Speaker 3>one single entity. It's the ultimate form of collectivism in
<v Speaker 3>the universe. It's a truly bizarre state of matter.
<v Speaker 2>Okay, so box one is the bosons. We are all
<v Speaker 2>one crowd, the conformists, the party animals.
<v Speaker 3>The ultimate collectivists.
<v Speaker 2>Now let's look at box two. The fermions.
<v Speaker 3>Ah, the fermions. They are the polar opposis in every
<v Speaker 3>conceivable way. If bosons are the force, fermions are the stuff, stuff,
<v Speaker 3>the building blocks of matter. We're talking about electrons, protons, neutrons,
<v Speaker 3>everything that has mass and takes up space is made
<v Speaker 3>of fermions.
<v Speaker 2>And if bosons are social.
<v Speaker 3>Then fermions are deeply aggressively antisocial.
<v Speaker 2>They need their personal space.
<v Speaker 3>They demand it. It's not a preference, it's a law.
<v Speaker 3>They obey a rule called the poly exclusion principle, and
<v Speaker 3>it is arguably the most important rule for our existence.
<v Speaker 2>The strictest rule in the book I read it is.
<v Speaker 3>It states very simply that no two fermions can occupy
<v Speaker 3>the exact same quantum state at the same time period.
<v Speaker 2>So if I'm an electron and I'm spinning up in
<v Speaker 2>this particular spot with this particular.
<v Speaker 3>Energy, then that spot is taken.
<v Speaker 2>No one else is allowed to spin up in this spot.
<v Speaker 3>Correct, You are the sole owner of that quantum state.
<v Speaker 3>If another electron tries to squeeze in it gets repelled.
<v Speaker 3>It has to go find a different energy level, a
<v Speaker 3>different location, or a different spin. It has to find
<v Speaker 3>its own unique address in the universe.
<v Speaker 2>How I always thought of exclusion as a negative thing,
<v Speaker 2>but the article points out that we actually owe our
<v Speaker 2>very lives to this an antisocial behavior.
<v Speaker 3>We absolutely do. Our existence is a monument to the
<v Speaker 3>stubbornness of fermions. How so, well, think about a simple atom.
<v Speaker 3>You have the nucleus in the center and electrons orbiting
<v Speaker 3>around it in shells. If electrons were social, like boosons,
<v Speaker 3>what would they do? They would all rush to the
<v Speaker 3>lowest possible energy state. They'd all pile up right next
<v Speaker 3>to the nucleus.
<v Speaker 2>They'd all crash into the center.
<v Speaker 3>The atom would implode. It would be a tiny, dense
<v Speaker 3>and chemically inert little ball. There would be.
<v Speaker 2>No structure and no chemistry.
<v Speaker 3>There would be no chemistry. The reason chemistry exists the
<v Speaker 3>entire beautiful complexity of the periodic table. The reason carbon
<v Speaker 3>bonds with four things and oxygen bonds with two is
<v Speaker 3>because the electrons are forced by the exclusion principle to
<v Speaker 3>stack up in shells.
<v Speaker 2>It's like filling seats in a theater exactly.
<v Speaker 3>Sorry, the first row is full, you have to go
<v Speaker 3>to the second row. Second row is full up to
<v Speaker 3>the balcony with you. That stacking creates different energy levels,
<v Speaker 3>and it's the electrons in the outer or most partially
<v Speaker 3>filled shell that do all the interesting work of forming
<v Speaker 3>chemical bonds.
<v Speaker 2>So the fact that my hand doesn't pass through this table,
<v Speaker 2>the very concept of solidity, it's fermions is basically because
<v Speaker 2>fermions are stubborn introverts who refuse to share a seat.
<v Speaker 3>Precisely, you are pushing against a wall of electrons that
<v Speaker 3>are all saying this spot is taken. Boson attraction gives
<v Speaker 3>us forces like light and heat. Fermion repulsion gives us
<v Speaker 3>structure and solidity. That fundamental tension is what builds the
<v Speaker 3>universe as we know it.
<v Speaker 2>And for a long long time we thought that was it.
<v Speaker 2>That was the complete menu. You check the box boson
<v Speaker 2>or fermion, Yeah, end of list.
<v Speaker 3>It seemed complete. The math was elegant, and it explained
<v Speaker 3>everything we could see and measure in our three dimensional world.
<v Speaker 2>But why I love a good rule, But why only two?
<v Speaker 2>Why can't we have a particle that's like mostly a
<v Speaker 2>loner but likes to hang out on weekends. Why is
<v Speaker 2>nature so binary?
<v Speaker 3>That is the exact qurdon that kept physicists up at night.
<v Speaker 3>Why are there no others? It seems too simple, almost
<v Speaker 3>our arbitrary.
<v Speaker 2>It does.
<v Speaker 3>And the answer, strangely enough, isn't really about the particles themselves.
<v Speaker 3>It's not an inherent property of an electron that makes
<v Speaker 3>it affermion. It's about the math of how they move.
<v Speaker 3>It comes down to a really deep and weird concept
<v Speaker 3>called indistinguishability.
<v Speaker 2>Okay, the article used a marble analogy here, and I
<v Speaker 2>want to walk through this slowly because usually when people
<v Speaker 2>start talking about quantum statistics, my eyes glaze over. But
<v Speaker 2>this actually made sense to me.
<v Speaker 3>It's a very helpful visualization. Let's do it. Imagine you
<v Speaker 3>have a table in front of you. On that table,
<v Speaker 3>you have two marbles. They look absolutely identical, same size,
<v Speaker 3>same glass, same color.
<v Speaker 2>Got it. Two marbles in our.
<v Speaker 3>Everyday world, what we call classical physics. You can still
<v Speaker 3>tell them apart because you can label them, even if
<v Speaker 3>it's just in your mind. You can say that's the
<v Speaker 3>marble on the left, and that's the marble on the right.
<v Speaker 3>If I were to paint one red and one blue,
<v Speaker 3>and then I swapped their positions, you know I swapped them.
<v Speaker 3>It's an observable event, right, I see.
<v Speaker 2>The red one move to the right, blue and to
<v Speaker 2>the left. No ambigiity, exactly.
<v Speaker 3>Even if I don't paint them, you can, in principle
<v Speaker 3>watch them move. You can track their individual paths through space.
<v Speaker 3>You can say, marble A went here, marble BU went there.
<v Speaker 3>They are distinct entities.
<v Speaker 2>Okay, that makes sense. That's our normal, intuitive world.
<v Speaker 3>Now let's shrink down to the quantum level. We have
<v Speaker 3>two electrons on our table.
<v Speaker 2>Okay, first problem.
<v Speaker 3>You cannot paint an electron. You cannot put a tiny
<v Speaker 3>little sticker on it that says, hello, my name is
<v Speaker 3>electron Bob.
<v Speaker 2>They are fundamentally generic.
<v Speaker 3>They are more than generic. They are indistinguishable. There is
<v Speaker 3>no measurement in the universe that can tell one electron
<v Speaker 3>from another. They are identical in mass, charge, spin, every
<v Speaker 3>single property. They are perfect clones.
<v Speaker 2>So there's no electron on the left, an electron on
<v Speaker 2>the right. There's just electron.
<v Speaker 3>There is just electron ness in two locations. So here's
<v Speaker 3>the scenario. You have two electrons. You close your eyes
<v Speaker 3>for a second. While your eyes are closed, I swap
<v Speaker 3>their positions. You open your eyes. What do you see?
<v Speaker 2>I see exactly what I saw before, two electrons in
<v Speaker 2>the same spots.
<v Speaker 3>Precisely. The universe looks identical. The final state is physically
<v Speaker 3>indistinguishable from the initial state. But and this is the
<v Speaker 3>absolute core of all quantum weirdness. We describe these particles
<v Speaker 3>with a mathematical formula called a wave function.
<v Speaker 2>Right, the thing that describes the probabilities of where it
<v Speaker 2>is and what it's doing exactly.
<v Speaker 3>And just because the physical scene looks the same doesn't
<v Speaker 3>mean the math of the wave functions stayed the same.
<v Speaker 3>Something can change under the hood. So an invisible change happened,
<v Speaker 3>an invisible mathematical change. When we swapped two identical particles,
<v Speaker 3>the total wave function of the system gets multiplied by
<v Speaker 3>a number. Let's call it the exchange factor. It's a
<v Speaker 3>phase factor technically, but exchange factor works just fine.
<v Speaker 2>The exchange factor. Okay, So every time they swap, the
<v Speaker 2>math gets tweaked by this factor exactly.
<v Speaker 3>Now let's complete the operation. Imagine I swapped them again.
<v Speaker 2>So we swap them and then we immediately swap them back.
<v Speaker 3>Right, we've performed two exchanges. Logically, if I swapped them twice,
<v Speaker 3>everything should be back to exactly where we started. Right,
<v Speaker 3>not just physically, but mathematically too. We've done an operation
<v Speaker 3>and then undone it.
<v Speaker 2>Yes, swap A to B, then B back to A.
<v Speaker 2>We are back at the start. No net change.
<v Speaker 3>So mathematically, if we multiplied by the exchange factor once
<v Speaker 3>and then multiplied by it again, the final result must
<v Speaker 3>be one, because multiplying by one represents no change.
<v Speaker 2>Okay, I'm with you. The exchange factor multiplied by itself,
<v Speaker 2>the exchange factor squared must equal one exactly.
<v Speaker 3>So popquz. Thinking about all the numbers in the universe,
<v Speaker 3>what numbers when you multiply them by themselves equal positive one?
<v Speaker 2>Well, one one times one is one.
<v Speaker 3>Correct, that's the boson. The exchange factor is plus one
<v Speaker 3>when you swap two bosons. The wave function doesn't change
<v Speaker 3>at all. It's multiplied by one. We say the wave
<v Speaker 3>function is symmetric under exchange, and.
<v Speaker 2>Wait, negative one negative one times negative one is also
<v Speaker 2>positive one.
<v Speaker 3>Bingo. That's the fermia. The exchange factor is negative one
<v Speaker 3>when you swap two fermions. The wave function flips its sign,
<v Speaker 3>it becomes negative what it was before. Okay, so it inverts,
<v Speaker 3>it inverts, it's antisymmetric. And that negative sign, that simple minus,
<v Speaker 3>is the mathematical root of that entire poly exclusion principle
<v Speaker 3>we talked about. The math forbids them from being in
<v Speaker 3>the same state, because if they were, the wave function
<v Speaker 3>would have to be zero, meaning they can't exist there.
<v Speaker 2>Wow, So all of chemistry comes from a minus sign.
<v Speaker 3>In a very real sense.
<v Speaker 2>Yes.
<v Speaker 3>Now for the critical question, are there any other real
<v Speaker 3>numbers that, when squared give you one?
<v Speaker 2>Uh? No, just plus one and minus one. That's it.
<v Speaker 3>That's it, and that is why the binary exists. The
<v Speaker 3>fundamental mathematics of swapping two things in our three D
<v Speaker 3>space forces the exchange factor to be either plus one
<v Speaker 3>or menic one. There is no room for anything else.
<v Speaker 3>The universe's operating system only allows those two options.
<v Speaker 2>It feels so rigid. Yeah, it's like finding out that
<v Speaker 2>the reason we only have vanilla and chocolate ice cream
<v Speaker 2>is because the ice cream machine literally cannot freeze any
<v Speaker 2>other flavor. The physics of the machine forbids it.
<v Speaker 3>That's a great way to put it. The machine our
<v Speaker 3>three dimensional universe was fundamentally limiting the menu.
<v Speaker 2>But and this is the beyond the binary part of
<v Speaker 2>our whole conversation. It turns out the machine is only
<v Speaker 2>limited if it's a three D machine.
<v Speaker 3>Correct. This is where the story pivots completely. This is
<v Speaker 3>where we break out of the prison.
<v Speaker 2>The source material quotes Professor Thomas Bush from Oyest asking
<v Speaker 2>that exact question we posed earlier, why are there no others?
<v Speaker 2>And the answer is there are others, but they can't
<v Speaker 2>exist in three dimensions. They need to live in flat land.
<v Speaker 3>Yes, to break the binary, we have to do something
<v Speaker 3>that sounds impossible. We have to delete a dimension. We
<v Speaker 3>have to go from three D to two D.
<v Speaker 2>This is the part I really want to visualize because
<v Speaker 2>it's so counterintuitive. Why does flattening the universe suddenly break
<v Speaker 2>that strict math rule? Why does x squared equals one
<v Speaker 2>stop being? The only answer?
<v Speaker 3>It has to do with topology. It's about the geometry
<v Speaker 3>of the paths the particles take when they swap. Okay,
<v Speaker 3>let's go back to our classical world for a moment.
<v Speaker 3>Think about two airplanes flying in the sky. That's a
<v Speaker 3>three D space.
<v Speaker 2>Okay, I've got plane A and plane B.
<v Speaker 3>In my head, if plane A wants to swap positions
<v Speaker 3>with plane B, it has an infinite number of options. Right, sure,
<v Speaker 3>it can fly over B under B to the left,
<v Speaker 3>to the right, it can do a huge loop to
<v Speaker 3>loop and come in from behind. The space is wide.
<v Speaker 2>Open, right, plenty of room to maneuver.
<v Speaker 3>Crucially, because there is so much empty space, specifically that
<v Speaker 3>third dimension of height, the paths the planes take never
<v Speaker 3>have to get tangled up with each other. You can
<v Speaker 3>always find a way to smoothly deform the path plane
<v Speaker 3>A took and shrink it down to nothing without ever
<v Speaker 3>hitting the path of plane B.
<v Speaker 2>Okay, so their histories, their flight paths are independent.
<v Speaker 3>In topology the math of shapes, we say that the
<v Speaker 3>swap is trivial. It leaves no lasting trace on the system.
<v Speaker 3>And that's the key. Because the swap is trivial. When
<v Speaker 3>you do it twice, you have to get back to
<v Speaker 3>where you started. The universe forgets the swap happened, which
<v Speaker 3>is why the math forces you back to one.
<v Speaker 2>But now let's squash the world. Let's take away that
<v Speaker 2>third dimension. We are in two D. We're like two
<v Speaker 2>coins sliding on a table top.
<v Speaker 3>Exactly. Now, imagine coin A wants to swap places with COINB.
<v Speaker 3>It cannot lift off the table. It has to slide
<v Speaker 3>around COINB.
<v Speaker 2>Okay, yeah, it has to skirt around it.
<v Speaker 3>Now it has a choice. Does it go clockwise or
<v Speaker 3>does it go counterclockwise?
<v Speaker 2>Does it matter which way it goes.
<v Speaker 3>In two D? It matters immensely. This is the entire trick.
<v Speaker 3>Because you can't lift the coin off the table. You
<v Speaker 3>can't just undo that loop you made. Think about it
<v Speaker 3>this way. If I walk around you clockwise holding one
<v Speaker 3>end of a rope, and you hold the other, and
<v Speaker 3>then I walk back to my starting spot, the rope
<v Speaker 3>is now wrapped around you once.
<v Speaker 2>Oh, I see. In three D I could just lift
<v Speaker 2>the rope over your head and it would be untangled.
<v Speaker 2>In two D, the rope is stuck. The tangle is
<v Speaker 2>real exactly.
<v Speaker 3>The paths get tangled. We call this phenomenon braiding. The world.
<v Speaker 3>Lines of the particles paths through spacetime get braided together
<v Speaker 3>like strands of hair.
<v Speaker 2>That is such a cool image. The history of the
<v Speaker 2>particles movement is a literal braid in space time.
<v Speaker 3>And because the system is braided, it has a memory.
<v Speaker 3>The universe remembers that the particles swap, and it remembers
<v Speaker 3>how they swapped clockwise or counterclockwise. And because it remembers,
<v Speaker 3>you don't have to go back to the exact starting
<v Speaker 3>state when you swap them twice.
<v Speaker 2>So the rule swap plus swap must equal one breaks down.
<v Speaker 3>It breaks down completely. The phase factor, that exchange factor
<v Speaker 3>no longer has to be just plus one or megas one.
<v Speaker 3>It can be any complex number. It can represent a
<v Speaker 3>rotation by any angle, so.
<v Speaker 2>It can be halfway in between. It can be ten
<v Speaker 2>percent boson, ninety percent fermion, it can be any any on,
<v Speaker 2>anything goes.
<v Speaker 3>The term was coined by the Nobel laureate Frank Wilchek
<v Speaker 3>back in the early eighties. He realized that in two dimensions,
<v Speaker 3>the rules of quantum statistics could be fundamentally different. You
<v Speaker 3>could have particles that were neither bosons nor fermions, but
<v Speaker 3>something in between.
<v Speaker 2>So these particles, these enions, they occupy that vast gray area.
<v Speaker 2>They aren't totally social, but they aren't totally antisocial either.
<v Speaker 2>They have their own unique set of rules.
<v Speaker 3>They have what's called fractional statistics. Their exchange behavior is
<v Speaker 3>a fraction of what you'd see with the normal particles,
<v Speaker 3>and this allows for entirely new types of collective behaviors,
<v Speaker 3>things that are just flat out impossible in our normal
<v Speaker 3>three D world.
<v Speaker 2>Okay, this sounds like some really out there theoretical physics.
<v Speaker 2>Have we actually seen these? Is this real or is
<v Speaker 2>it just a fever dream on a whiteboard?
<v Speaker 3>Oh, it's real, we have It took about forty years
<v Speaker 3>from the theoretical prediction to the experimental proof, but in
<v Speaker 3>twenty twenty researchers at a lab in France finally observed
<v Speaker 3>Enians experimentally.
<v Speaker 2>But wait a minute, we live in three D. How
<v Speaker 2>did they find two D particles in our three D world?
<v Speaker 3>They had to build a trap. They had to create
<v Speaker 3>an artificial two D universe. They used very special materials semiconductors,
<v Speaker 3>and cool them down to near absolute zero, and then
<v Speaker 3>applied massive magnetic fields.
<v Speaker 2>So they create extreme conditions, very extreme.
<v Speaker 3>And those conditions force the electrons in the material to
<v Speaker 3>stop moving up and down. They get locked into moving
<v Speaker 3>in a strictly two dimensional layer right at the interface
<v Speaker 3>between materials, like.
<v Speaker 2>They're skating on the surface of a frozen pond.
<v Speaker 3>A perfect analogy. And when you can find them like that.
<v Speaker 3>When you force them to live in flatland, the electrons
<v Speaker 3>stop behaving like fermions, they start acting like Enians. The
<v Speaker 3>brading effect takes over.
<v Speaker 2>Okay, so twenty twenty was the year the two D Aenian.
<v Speaker 2>We proved the gray area exists.
<v Speaker 3>That's a huge deal in itself, massive deal, a no
<v Speaker 3>bellworthy discovery, many would say.
<v Speaker 2>But the paper we are discussing today, this oist research,
<v Speaker 2>this takes it another step further. They're not satisfied with
<v Speaker 2>two DALs.
<v Speaker 3>No, we are going from flatland to lineland.
<v Speaker 2>One dimension, the ultimate constraint.
<v Speaker 3>This is the work of Jack Featherstone, Raoul hid Algo
<v Speaker 3>Sokoto and their colleagues. And they asked a very simple
<v Speaker 3>but very profound question, what happens if we take away
<v Speaker 3>the around entirely right? One Dephysics is fascinatingly weird. Let's
<v Speaker 3>go back to our analogies. Imagine beads on a string
<v Speaker 3>or cars on a one lane road.
<v Speaker 2>Okay, beads on a string. I'm with you.
<v Speaker 3>In three D, we fly over. In two D, we
<v Speaker 3>slide around and get braided. In one D. How do
<v Speaker 3>two beads on a string swap places.
<v Speaker 2>They can't. If I'm on the string and you're on
<v Speaker 2>the string and I want to get to the other
<v Speaker 2>side of you, I'm stuck, of least, unless I go
<v Speaker 2>through you bingo.
<v Speaker 3>There is no left or right. There is no up
<v Speaker 3>or down. There is only forward or backward. So for
<v Speaker 3>particles to swap in a one dimensional system, they must
<v Speaker 3>transmit through one another.
<v Speaker 2>Like ghosts. They just phase through each other in.
<v Speaker 3>A quantum sense. Yes, it's a collision, but a quantum
<v Speaker 3>collision where they can tunnel through each other. And this interaction,
<v Speaker 3>this moment of passing through is where the brand new
<v Speaker 3>discovery lies.
<v Speaker 2>Okay, so what's new about that?
<v Speaker 3>Well, in the two D case, the behavior of the
<v Speaker 3>Enian is usually a fixed property of the material. You
<v Speaker 3>buy the semiconductor, you do the experiment, you get the
<v Speaker 3>any and you get the braiding statistic is locked in.
<v Speaker 2>You can't change the settings, right.
<v Speaker 3>But in this new one DE proposal, the researchers at
<v Speaker 3>OST and the University of Oklahoma found that the enianness,
<v Speaker 3>where the particle sits on that spectrum between Boson and fermion,
<v Speaker 3>isn't a fixed property. It depends entirely on that moment
<v Speaker 3>of collision.
<v Speaker 2>What about it?
<v Speaker 3>It depends on how strongly the particles interact when they
<v Speaker 3>pass through each other, and.
<v Speaker 2>Can we control that? Can we control how strongly they interact?
<v Speaker 3>We can control it with incredible precision. And this is
<v Speaker 3>the magic word from the paper. They call it a
<v Speaker 3>tunable exchange factor.
<v Speaker 2>Tunable. Okay, that's the magic word. That sounds important.
<v Speaker 3>It changes everything. It means we aren't just hunting for
<v Speaker 3>new particles in the wild anymore. We are building a
<v Speaker 3>system where we can literally dial them in. Imagine you
<v Speaker 3>have a slider on a mixing board in a recording studio.
<v Speaker 2>Okay, I can picture that slide.
<v Speaker 3>It all the way to the left. You set the
<v Speaker 3>interaction to be very wet. The particles pass through each
<v Speaker 3>other easily, almost like they don't see each other. In
<v Speaker 3>that case, they act like bosons.
<v Speaker 2>Okay, the social particles.
<v Speaker 3>Now it all the way to the right. You crank
<v Speaker 3>up the interaction strength. Now when they meet, they bounce
<v Speaker 3>off each other hard, They refuse to pass through.
<v Speaker 2>They act like fermions, the antisocial particles.
<v Speaker 3>And the incredible part is the middle. As you move
<v Speaker 3>that slider from left to right, as you adjust the
<v Speaker 3>interaction strength. You can smoothly transform the particles through every
<v Speaker 3>possible shade of any or all.
<v Speaker 2>Wait, really, so you can have a particle that is
<v Speaker 2>thirty seven percent fermion and then just nudge a dial
<v Speaker 2>and make it thirty eight percent.
<v Speaker 3>That is exactly what their theoretical model predicts.
<v Speaker 2>It is. It feels like cheating. It feels like we're
<v Speaker 2>hacking the source code of reality. Yeah, taking an electron
<v Speaker 2>and telling it no, today, you're not going to be
<v Speaker 2>an electron today, You're going to act a bit more
<v Speaker 2>like a photon.
<v Speaker 3>Essentially, Yes, we are decoupling the identity of the particle
<v Speaker 3>from its statistical behavior. The behavior becomes a choice we
<v Speaker 3>make in the lab. It's an engineered property of the system,
<v Speaker 3>not an innate property of the particle.
<v Speaker 2>This sounds incredibly difficul So how do they actually do this?
<v Speaker 2>You mentioned ultra cool atomic systems. Is this something that
<v Speaker 2>exists or is it just a blueprint for a future machine.
<v Speaker 3>The beauty of this paper, and this is why I
<v Speaker 3>was published in a journal like Physical Review A, is
<v Speaker 3>that it's a recipe. It's a detailed set of instructions
<v Speaker 3>for an experiment that can be done with equipment that
<v Speaker 3>already exists in labs today.
<v Speaker 2>We already have the kitchen to cook this up.
<v Speaker 3>We do labs around the world, including at ost or experts.
<v Speaker 3>In this they use powerful lasers to create something called
<v Speaker 3>an optical lattice. It's like an egg carton made of light,
<v Speaker 3>and they can shape these laser beams to create a
<v Speaker 3>rays of incredibly narrow tubes of light. The tubes are
<v Speaker 3>so narrow that the atoms they trap inside can only
<v Speaker 3>move forward and backward. They can't move side to side.
<v Speaker 3>That's your one D string.
<v Speaker 2>So they literally build these one dimensional universes for atoms
<v Speaker 2>to live in.
<v Speaker 3>They do it's routine, which is still amazing to think about.
<v Speaker 2>And the tuning knob, the slider that controls the interaction.
<v Speaker 2>How does that work?
<v Speaker 3>For that, they use magnetic fields. There's a wonderful phenomenon
<v Speaker 3>in atomic physics called a Feshbach resonance. The details are complex,
<v Speaker 3>but the upshot is simple. By tweaking an external magnetic field,
<v Speaker 3>you can make the atoms in the trap attract each
<v Speaker 3>other or repel each other with almost any strength you want.
<v Speaker 2>So the magnetic field is the slider.
<v Speaker 3>The magnetic field is the slider. You want them to
<v Speaker 3>be bosons. Set the field to this value. You want
<v Speaker 3>them to be fermions. Set it to that value. You
<v Speaker 3>want a very specific type of enion dial in the
<v Speaker 3>magnet to precisely two point three gas or whatever the
<v Speaker 3>number is.
<v Speaker 2>So the theory is solid, the equipment is ready. But
<v Speaker 2>here's the big question. How do you know it worked.
<v Speaker 2>You can't see an atom with your eyes. You certainly
<v Speaker 2>can't see its personality or its quantum statistics.
<v Speaker 3>You watch how they run away. It's a technique called
<v Speaker 3>time of flight imaging, and the thing they measure is
<v Speaker 3>the momentum distribution. Imagine you have your one D tube
<v Speaker 3>full of these ultra coold atoms. You've set the magnetic
<v Speaker 3>field to create your enions. Then suddenly you turn off
<v Speaker 3>the lasers.
<v Speaker 2>The trap disappears.
<v Speaker 3>The trap disappears, The gas, which was tightly confined, is
<v Speaker 3>now free to expand.
<v Speaker 2>It explodes outward and a.
<v Speaker 3>Very gentle, cold quantum way. Yes, and how it expands
<v Speaker 3>tells you everything you need to know. Okay, if the
<v Speaker 3>particles inside were bosons, they like to clump together. They
<v Speaker 3>have a very low relative momentum, so when they expand,
<v Speaker 3>they do so in a specific, dense, focused pattern.
<v Speaker 2>Right, the socialites stick together.
<v Speaker 3>If they were fermions, they avoid each other. They have
<v Speaker 3>a high relative momentum, so they fly apart much faster
<v Speaker 3>and the cloud spreads out much more broadly.
<v Speaker 2>The introverts run for the.
<v Speaker 3>Exits exactly, and if they are these new one d enions,
<v Speaker 3>we'll do.
<v Speaker 2>Something in between.
<v Speaker 3>They will produce a specific, unique signature that is somewhere
<v Speaker 3>in between. The paper by Hidalgo, Sokota and Featherstone essentially
<v Speaker 3>gives experimentalists a chart, a field guide. It says, if
<v Speaker 3>you tune the magnet to this setting to create this
<v Speaker 3>type of anenion, and then you release the gas, the
<v Speaker 3>spray pattern should look exactly like this.
<v Speaker 2>It's like identifying a bird by its flight pattern because
<v Speaker 2>you can't see its feathers.
<v Speaker 3>That's a lovely image. Yes, that's precisely it. We can't
<v Speaker 3>see the internal state, but we can infer it with
<v Speaker 3>incredible accuracy by observing the collective behavior.
<v Speaker 2>So Professor Bush is quoted in the press release saying
<v Speaker 2>this opens the door to improving our understanding of the
<v Speaker 2>fundamental properties of the quantum world, which is a very
<v Speaker 2>polite reserve scientist way of saying, this is a big deal.
<v Speaker 3>A very big deal.
<v Speaker 2>But why let's bring it back to the listener. Why
<v Speaker 2>should we care that we can make atoms act weirdly
<v Speaker 2>in a super cold tube. What's the payoff?
<v Speaker 3>The payoff is about control, and about a concept called emergence.
<v Speaker 3>Emergence everything we see in the macroscopic world, properties like superconductivity, magnetism,
<v Speaker 3>the heat capacity of a material, whether something is an
<v Speaker 3>insulator or a conductor, all of these things are emergent properties.
<v Speaker 3>They emerge from the statistical rules of the trillions of
<v Speaker 3>particles that make up the material.
<v Speaker 2>So the little rules dictate the big picture.
<v Speaker 3>The little rules dictate everything, And for all of human
<v Speaker 3>history we've only been able to play with two sets
<v Speaker 3>of rules, Boson rules and Fermion rules. That's it.
<v Speaker 2>We're painting with only two colors, exactly.
<v Speaker 3>We're trying to paint a masterpiece with just red and blue.
<v Speaker 3>But if we can create systems with anions, and not
<v Speaker 3>just any anians, but tuneable anions, we suddenly have the
<v Speaker 3>whole color wheel, green.
<v Speaker 2>Purple, orange, all the infinite shades in between.
<v Speaker 3>We can start to ask questions like what kind of
<v Speaker 3>novel material would emerge if it's constituent particles had a
<v Speaker 3>statistical factor of say zero point seven. We don't know
<v Speaker 3>the answer because nature never gave us a material like that.
<v Speaker 2>But now we can build it.
<v Speaker 3>We can build it. We might discover new phases of matter,
<v Speaker 3>we might find new ways to guide energy with perfect efficiency.
<v Speaker 3>And the really big one is quantum computing.
<v Speaker 2>Topological quantum computing. I've heard that phrase. It's supposed to
<v Speaker 2>be the holy grail.
<v Speaker 3>It is the idea there is to use that braiding
<v Speaker 3>memory we talked about to store quantum information. You encode
<v Speaker 3>a bit of data into a not in space time.
<v Speaker 2>And because it's a not, it's stable. You can't just
<v Speaker 2>undo it by bumping into it.
<v Speaker 3>Precisely, it's naturally robust against noise from the environment, which
<v Speaker 3>is the biggest killer of quantum computers today. This research,
<v Speaker 3>by giving us a system where we can directly control
<v Speaker 3>the anianness of particles, is a massive stepping stone toward
<v Speaker 3>learning how to create and manipulate those kinds of robust
<v Speaker 3>topological states.
<v Speaker 2>So it moves us from just observing nature to actively
<v Speaker 2>designing it.
<v Speaker 3>That is a transition we are living through in quantum
<v Speaker 3>physics right now. For a century we were explorers mapping
<v Speaker 3>a strange new continent. Now we're becoming architects. We're learning
<v Speaker 3>how to build with the quantum bricks and mortar.
<v Speaker 2>It's incredibly exciting, but it also makes you realize how
<v Speaker 2>much of our reality, our physical laws are just local.
<v Speaker 3>They're contingent, they are local to our dimension.
<v Speaker 2>Right. That's the philosophical angle that just gets me. We
<v Speaker 2>think the laws of physics are these stone tablets brought
<v Speaker 2>down from the mountain. Thou shalt be a.
<v Speaker 3>Fermion, thou shalt obey the exclusion principle.
<v Speaker 2>Yes, but it turns out the laws are just suggestions
<v Speaker 2>that depend entirely on the geometry of the room you're
<v Speaker 2>standing in.
<v Speaker 3>Context is everything. In three D, the context is rigid,
<v Speaker 3>there's too much freedom of movement, so the weirdness gets
<v Speaker 3>washed out. In two D and one D the context
<v Speaker 3>is constrained, and that constraint allows these new, richer behaviors
<v Speaker 3>to emerge.
<v Speaker 2>It's so backwards from how you'd normally think. You think
<v Speaker 2>more freedom means more possibilities.
<v Speaker 3>But here less freedom, fewer dimensions means more possibilities for
<v Speaker 3>quantum statistics, So I have to ask.
<v Speaker 2>We've talked about going down in dimensions. We went from
<v Speaker 2>the rigid three D world to the braided two D
<v Speaker 2>world to this newly discovered tunable one D world.
<v Speaker 3>Right, we've gone from two choices to infinite fixed choices
<v Speaker 3>to infinite tunable choices. What happens if we go up
<v Speaker 3>into the fourth dimension? You mean a fourth spatial dimension?
<v Speaker 2>Yeah? Yeah. If three D limited is to just two options,
<v Speaker 2>does four you get restrict us even more? Or does
<v Speaker 2>it open up something totally new that we can't even imagine.
<v Speaker 3>That is a wonderful and a very deep thought experiment.
<v Speaker 3>Let's think about the braiding again. That's the key. In
<v Speaker 3>two D we got inians because the paths got tangled, right.
<v Speaker 3>In three D we lost the onions because we had
<v Speaker 3>that extra dimension to move in, which allowed us to
<v Speaker 3>untangle the paths.
<v Speaker 2>The rope could be lifted over the head.
<v Speaker 3>In four D you have even more room, you have
<v Speaker 3>another direction.
<v Speaker 2>To move in, so it's even easier to untangle things.
<v Speaker 3>It's so much easier that it breaks our intuition again.
<v Speaker 3>Mathematicians have shown that in four D space you can
<v Speaker 3>untie any knot in a piece of string. Without cutting
<v Speaker 3>the string. What you just lift part of the knot
<v Speaker 3>into the fourth direction, pass it under the other strand,
<v Speaker 3>and drop it back down. The knot just falls apart.
<v Speaker 2>So four D is hyper trivial when it comes to
<v Speaker 2>tangles exactly.
<v Speaker 3>So, following that logic, if we lived in a four
<v Speaker 3>D universe, the rules of particle exchange would likely be
<v Speaker 3>even simpler than they are here. The braiding that gives
<v Speaker 3>us enians in two D would be completely gone. You'd
<v Speaker 3>almost certainly just have bosons and fermions again.
<v Speaker 2>So the weirdness is a feature of low dimensions.
<v Speaker 3>It seems to be, or perhaps entirely new structures could
<v Speaker 3>emerge that rely on forty geometry we can't even visualize.
<v Speaker 3>Maybe you get new classifications based on hyper rotations. Maybe
<v Speaker 3>they have hyper bosons or something even stranger we don't know.
<v Speaker 2>It completely breaks the brain a little bit. It makes
<v Speaker 2>you wonder if there are forty creatures looking down at
<v Speaker 2>our plane of existence, watching us struggle with our bosons
<v Speaker 2>and fermions, and just thinking, oh, look at those cute
<v Speaker 2>little three D beings. They're stuck with their binary choices.
<v Speaker 3>Why don't they just rotate into the W axis to
<v Speaker 3>get around that problem.
<v Speaker 2>It's so simple, exactly, just sidestep time for a moment.
<v Speaker 2>It's easy.
<v Speaker 3>Well, until we figure out how to ascend to the
<v Speaker 3>fourth spatial dimension. It seems we have plenty of fascinating
<v Speaker 3>new physics to work with down here in one D.
<v Speaker 2>We certainly do so to recap this whole journey. Today,
<v Speaker 2>the universe isn't as black and white, not as binary
<v Speaker 2>as we thought, not at all. The boxes we've used
<v Speaker 2>for a century. Boson and Fermion are real, but they
<v Speaker 2>are just the end points of a vast, continuous spectrum
<v Speaker 2>that only reveals itself when you change the geometry of
<v Speaker 2>reality itself.
<v Speaker 3>And thanks to this new research from Oyist and the
<v Speaker 3>University Oklahoma, we now have a theoretical map and an
<v Speaker 3>experimental recipe to access that entire spectrum. We can finally
<v Speaker 3>turn the knob.
<v Speaker 2>It's a great reminder that when you're organizing your life
<v Speaker 2>or the universe, sometimes the problem isn't the stuff you're sorting,
<v Speaker 2>it's the boxes you're trying to force them into.
<v Speaker 3>Or maybe it's just the dimension of the drawer.
<v Speaker 2>I am definitely blaming the topology of my kitchen drawer
<v Speaker 2>for the mess next time. It's not my fault, honey,
<v Speaker 2>it's the non trivial brading of a spatulus.
<v Speaker 3>Good luck explaining that to your guests. I'm sure it
<v Speaker 3>will go over well.
<v Speaker 2>I'll give it a try. Thank you so much for
<v Speaker 2>walking us through this. This was a heavy one, but
<v Speaker 2>I really feel like I get it now.
<v Speaker 3>It was a pleasure. It's always good to stretch the
<v Speaker 3>mind a bit, and this topic certainly does that.
<v Speaker 2>And everyone listening, thanks for sticking with us as we
<v Speaker 2>went down this rabbit hole. Keep questioning the categories, keep
<v Speaker 2>looking for the gray areas, and remember the laws of
<v Speaker 2>physics might just be waiting for you to change your perspectives.
<v Speaker 3>Be curious.
<v Speaker 2>We'll see on the next one.