Speaker 1: Welcome to the quark Side. Quantum Physics Podcast, an exploration
Speaker 1: of the fundamental structure of reality, where quantum laws govern matter, energy,
Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
Speaker 1: and understanding begins at the smallest scales.
Speaker 2: Happy Valentine's Day. It is Saturday, February fourteenth, twenty twenty six.
Speaker 2: And look, I know exactly what you're thinking.
Speaker 3: Oh, I think they do two.
Speaker 2: You're expecting us to pivot into. I don't know the
Speaker 2: chemistry of oxytocin, or maybe the socioeconomic history of the
Speaker 2: greeting card industry.
Speaker 3: Or maybe why we give people roses which are covered
Speaker 3: in thorns. Seems like a mixed.
Speaker 2: Message, exactly a thorny flower as the ultimate symbol of affection.
Speaker 2: But we are going in a completely completely different direction.
Speaker 3: Today, a very very different direction.
Speaker 2: While the rest of the world is focusing on love,
Speaker 2: we're focusing on something well arguably more fundamental to the
Speaker 2: human experience, even if it sounds a lot less romantic.
Speaker 2: We are talking about precision, We're talking about order. We
Speaker 2: are talking about the ticking of the clock, but not
Speaker 2: just any clock. We are diving into a story that
Speaker 2: broke well essential yesterday about a strange, complicated, and frankly
Speaker 2: mind mending relationship between physics and time itself.
Speaker 3: It's a story about order, chaos and a state of
Speaker 3: matter that until very recently, and by recently I mean
Speaker 3: the last decade, people didn't even think could exist.
Speaker 2: Right.
Speaker 3: In fact, some very smart people proved it couldn't.
Speaker 2: Exist until they were proven wrong.
Speaker 3: Until they are proven wrong.
Speaker 2: Exactly, we are talking about time crystals. And before you
Speaker 2: hit pause or you know, roll your eyes, I need to.
Speaker 3: Make a disclaimer necessary one.
Speaker 2: No, we are not talking about an infinity stone from
Speaker 2: a Marvel movie. We aren't talking about a plot device
Speaker 2: from Doctor Who or some mystical New age healing stone
Speaker 2: you buy on Etsy to align your chakras.
Speaker 3: Although to be fair, the name time crystal does sound
Speaker 3: incredibly sci fi.
Speaker 2: Oh it's perfect sci fi.
Speaker 3: It sounds like something you'd find in a bad paperback
Speaker 3: novel from the nineteen seventies.
Speaker 2: It sounds totally made up. It sounds like flux capacitor.
Speaker 2: But it is hard science. We are talking about a
Speaker 2: new state of matter that breaks the rules of how
Speaker 2: we think structure and time actually work, and the reason
Speaker 2: we are talking about it today is because of our
Speaker 2: report that just came out.
Speaker 3: That's right. This comes from a report published yesterday February thirteen,
Speaker 3: twenty twenty six, on fizz dot org, written by Sam Jarman.
Speaker 3: But the core of our discussion, the meat on the bone,
Speaker 3: is based on a new study published in Physical Review Letters.
Speaker 2: Which, for those who don't follow the academic publishing horse race,
Speaker 2: is pretty much the heavy hitter of physics journals.
Speaker 3: Oh, it's the top tier.
Speaker 2: If you're publishing in PRL, you aren't just speculating, you've
Speaker 2: got the receipts.
Speaker 3: It is the gold standard. The research was led by
Speaker 3: lu Milaviati at the Abdessalam International Center for Theoretical Physics
Speaker 3: in Italy, and what they have put for word is well.
Speaker 2: It's a blueprint, a blueprint for what exactly.
Speaker 3: Or a clock, but not a clock like the one
Speaker 3: on your wall or even the one on your phone.
Speaker 3: They are proposing a quantum clock built on the backbone
Speaker 3: of these time crystals.
Speaker 2: So our mission today is to unpack this. We need
Speaker 2: to understand what these exotic systems are, and that is
Speaker 2: the technical term exotic, which usually means we don't fully
Speaker 2: understand it yet.
Speaker 3: Right, it's physics code for it.
Speaker 2: This is weird and how they could revolutionize everything from
Speaker 2: how we navigate the globe to how we detect magnetic fields.
Speaker 3: And honestly, it touches on the fundamental limits of quantum mechanics.
Speaker 3: It's not just about knowing what time it is. It's
Speaker 3: about understanding the nature of time itself and how we
Speaker 3: measure it against the background of a chaotic universe.
Speaker 2: Okay, that is a big promise. But before we get
Speaker 2: to the philosophy, we have to get through the physics.
Speaker 2: And I want to do this right. We aren't going
Speaker 2: to skim the surface today.
Speaker 3: Noh, let's get into the weeds.
Speaker 2: We are going to get into the weeds because that's
Speaker 2: where the interesting stuff is. So let's start at the
Speaker 2: very beginning. The phrase time crystal. It combines two words
Speaker 2: we know, but puts them together in a way that
Speaker 2: feels wrong.
Speaker 3: It does feel wrong.
Speaker 2: We know what a crystal is, diamonds, quartz, salt, ice, right,
Speaker 2: but when a physicist says crystal, what are they actually defining?
Speaker 2: Because I assume they aren't talking about jewelry.
Speaker 3: So yeah, let's strip away the aesthetic aspect. Yeah, in
Speaker 3: condensed matter physics, A crystal is defined very simply as
Speaker 3: a system that breaks spatial translation symmetry.
Speaker 2: Okay, you drop the s word early symmetry. We need
Speaker 2: to unpack that immediately. What does it mean to break
Speaker 2: spatial translation symmetry?
Speaker 3: Okay? Imagine you are floating in an infinite empty void,
Speaker 3: or simpler, imagine a perfectly smooth, infinite pool of water.
Speaker 3: It is completely uniform. Got it. If you close your
Speaker 3: eyes and I move you three feet to the left
Speaker 3: and you open your eyes, does the world look different, No, it.
Speaker 2: Looks exactly the same.
Speaker 3: It's just more water exactly. That system has continuous spatial
Speaker 3: translation symmetry. The laws of physics and the arrangement of
Speaker 3: matter are the same everywhere. It doesn't matter where you are.
Speaker 3: But now let's freeze that water into ice.
Speaker 2: Okay, so now we have a solid block.
Speaker 3: But if you zoom in with a microscope, that ice
Speaker 3: isn't smooth anymore. The water molecules have locked into a
Speaker 3: rigid lattice structure a pattern. A pattern. Maybe they are
Speaker 3: arranged in hexagons. Now, if you stand on a molecule
Speaker 3: and I move you a tiny bit to the left, say,
Speaker 3: into the empty space between molecules, does the world look different.
Speaker 2: Yes, because now I'm not on a molecule anymore. I'm
Speaker 2: in the gap.
Speaker 3: Correct. But if I move you exactly one lattice unit
Speaker 3: to the last ye, the exact distance between two molecules,
Speaker 3: you land on another molecule and it looks the same again.
Speaker 2: So the symmetry isn't continuous anymore. I can't just move
Speaker 2: any distance and have it look the same.
Speaker 3: That's it.
Speaker 2: I have to move specific, discrete distances to see the
Speaker 2: same pattern exactly.
Speaker 3: The formation of the crystal has broken the continuous symmetry
Speaker 3: of space. It has chosen a specific pattern. It has
Speaker 3: imposed order on the chaos. We call this a crystal,
Speaker 3: a repeating pattern in space.
Speaker 2: Okay, of salt, diamonds, checkerboards, they all break spatial symmetry. Now,
Speaker 2: how do we get to a time crystal? Because my
Speaker 2: brain wants to imagine a diamond that travels through time,
Speaker 2: which I know is wrong.
Speaker 3: That is wrong, but it's a fun image.
Speaker 2: That is a good image.
Speaker 3: No, to understand a time crystal, you have to take
Speaker 3: that same logic we just use for space and apply
Speaker 3: it to time.
Speaker 2: So time has symmetry.
Speaker 3: In physics, yes, we have time translation symmetry. It basically
Speaker 3: means that the laws of physics don't care when you
Speaker 3: run an experiment. If you mix baking soda and vinegar
Speaker 3: today at noon, it bubbles. If you do it tomorrow
Speaker 3: at midnight, it bawls. The same way. The laws are
Speaker 3: constant in time, energy is conserved, the system is stable.
Speaker 2: Okay, So breaking that symmetry would mean what that the
Speaker 2: laws of physics change.
Speaker 3: Not that the laws change, but that the system itself
Speaker 3: refuses to be constant in time. It means that even
Speaker 3: in its lowest energy state, its most comfortable rested state,
Speaker 3: it is changing. It is moving.
Speaker 2: Okay, let's unpack that sattern repeating in time.
Speaker 3: Imagine a material that, instead of looking the same, if
Speaker 3: you look three inches to the left, it.
Speaker 2: Looks the same if you look three seconds later.
Speaker 3: That's exactly it. It has a configuration that oscillates, it
Speaker 3: returns to its original state. It fixed intervals. It has
Speaker 3: a temporal structure. It effectively creates its own timeline. Tick
Speaker 3: tick tick.
Speaker 2: But wait, I have to play the skeptic here. Isn't
Speaker 2: that just anything that moves like a clock pendulum repeats
Speaker 2: in time? My heart beats in time. The turn signal
Speaker 2: on my car repeats in time. Why are those not
Speaker 2: time crystals? Why do we need a fancy new term
Speaker 2: for vibration.
Speaker 3: That is the million dollar question, and this is where
Speaker 3: it gets subtle and where we have to talk about thermodynamics.
Speaker 3: A pendulum, a heart, a turn signal. They all need
Speaker 3: energy to keep going. They need fuel. If you stop
Speaker 3: winding the Grandfather clock, the pendulum stops because of friction
Speaker 3: and air resistance. If you stop powering the turn signal,
Speaker 3: the light goes off. They are constantly losing energy to heat.
Speaker 3: They eventually wind down to a stop to equilibrit Right.
Speaker 2: Entropy comes for us. All the universe wants to be
Speaker 2: a lukewarm soup.
Speaker 3: Ideally, yes, yeah. In a standard system, the ground state,
Speaker 3: the state of lowest energy, where the system settles when
Speaker 3: you take away all the heat and excitement. Is static.
Speaker 3: It's motionless, a rock sitting at the bottom of a hill.
Speaker 2: But for a time crystal. You're saying, the ground state
Speaker 2: itself is moving.
Speaker 3: Precisely, a time crystal exhibits this repeating motion, this oscillation
Speaker 3: in its lowest possible energy state. It's not moving because
Speaker 3: you are pushing it. No external force, no external force.
Speaker 3: It's moving, because movement is its natural state of being.
Speaker 3: It breaks time translation symmetry spontaneously.
Speaker 2: WHOA stop there. You just described a system that moves
Speaker 2: forever in its ground state without energy input.
Speaker 3: I did.
Speaker 2: That sounds suspiciously like a perpetual motion machine. And the
Speaker 2: last time I checked, the first law of filmodynamics says
Speaker 2: no free lunch. Why isn't this violating physics?
Speaker 3: I love that you went there, because that was the
Speaker 3: exact controversy when this was first proposed. Image Nobel laureate
Speaker 3: Frank Wilchek propose this idea around twenty twelve, he asked,
Speaker 3: can a system break time symmetry the way a crystal
Speaker 3: breaks space symmetry? And the initial reaction for the community
Speaker 3: was basically, Frank, You've lost it. That's perpetual motion.
Speaker 2: So how is it not? How does it get around that?
Speaker 3: Because of the definition of work, A perpetual motion machine
Speaker 3: is impossible because it claims you can extract energy from
Speaker 3: it forever.
Speaker 2: Right, you can power something with it.
Speaker 3: You can hook it up to a turbine and power
Speaker 3: a light bulb a time crystal cannot do that?
Speaker 2: Why not? If it's moving, surely I can hook a
Speaker 2: gear to it.
Speaker 3: No, because the system is in its ground state, it
Speaker 3: has no excess energy to give you. If you try
Speaker 3: to hook a gear to it, you are interacting with it.
Speaker 3: You're adding resistance that collapses the quantum state. The moment
Speaker 3: you try to extract work, the time crystal breaks, it
Speaker 3: stops being a time crystal. So it moves forever, but
Speaker 3: it's useless for powering your car.
Speaker 2: So it's a closed loop.
Speaker 3: It's closed loop. It violates no laws because it generates
Speaker 3: no power.
Speaker 2: It's like a ghost pacing in a hallway. It's moving,
Speaker 2: but it can't turn a doorknob.
Speaker 3: That is a surprisingly accurate analogy. Yes, a perfect frictionless ghost.
Speaker 2: Okay, So Willcheck proposes this in twenty twelve, everyone says, maybe,
Speaker 2: then what happened because you mentioned we've known they exist
Speaker 2: for a decade.
Speaker 3: Well, there was a bit of drama. Some Japanese physicists
Speaker 3: Watanabi and Oshikawa proved a theorem, effectively saying will Check
Speaker 3: is wrong. You can't have a time crystal and thermal equilibrium.
Speaker 2: So it can't happen in that ground state you described, not.
Speaker 3: In a simple static equilibrium system. It was a heavy blow.
Speaker 3: It looked like the idea was dead.
Speaker 2: So the idea died.
Speaker 3: No, it pivoted. Physicists are clever. They realized, Okay, maybe
Speaker 3: we can't have them in perfect equilibrium, but what if
Speaker 3: we have them in a driven system, a system that
Speaker 3: we poke periodically, but the system responds in a weird way.
Speaker 2: This is what led to the twenty sixteen experiments.
Speaker 3: Exactly, in twenty sixteen, two different groups, one led by
Speaker 3: Chris Monroe and Maryland and another by Mikhyle Luken at
Speaker 3: Harvard created the first discrete time crystals.
Speaker 2: And how did they do that?
Speaker 3: They took ions, trap them in electromagnetic field, and hit
Speaker 3: them with lasers in a pulse bang bang, bang, a
Speaker 3: regular rhythm.
Speaker 2: So they were adding energy. That sounds like the pendulum.
Speaker 3: Again, they were adding energy. But here's the magic trick.
Speaker 3: They hit the system with a laser every t seconds.
Speaker 3: But the system didn't repeat every two seconds. It didn't
Speaker 3: know it repeated every two t seconds or three t seconds.
Speaker 3: It broke the symmetry of the driver. It adopted its own, slower,
Speaker 3: more stable rhythm.
Speaker 2: Wait, I want to make sure I get this. It's
Speaker 2: like if I'm jumping rope and the rope comes around
Speaker 2: every second, but I only jump every two seconds.
Speaker 3: Yes, you have created a new period that is different
Speaker 3: from the driving force. You're not just a puppet of
Speaker 3: the rope. You've established your own.
Speaker 2: Pattern and it holds that pattern rigidly, incredibly rigidly.
Speaker 3: That was the proof that the material was creating its
Speaker 3: own timeline. It wasn't just mirroring the laser. It was
Speaker 3: doing its own thing, locking into a sub harmonic frequency.
Speaker 2: So ten years ago we proved they exist. We found
Speaker 2: the loophole.
Speaker 3: We did We realized, Okay, nature actually allows this weird behavior. Yeah,
Speaker 3: but for the last ten years the conversation has been
Speaker 3: that's a cool party trick physics, but what can we
Speaker 3: actually do with it?
Speaker 2: It's the classic solution in search of.
Speaker 3: A problem exactly. And that brings us to twenty twenty
Speaker 3: six because the study we are looking at today, the
Speaker 3: Viati paper, moves the goalposts from look at this weird
Speaker 3: thing to let's build a machine with this.
Speaker 2: And the machine they want to build is the most
Speaker 2: precise clock in the universe.
Speaker 3: That's the ambition. And to understand why that is such
Speaker 3: a big deal, we have to talk about the villain
Speaker 3: of our story. The villain yes, the current status quill
Speaker 3: the atomic clock.
Speaker 2: Which begs the question what is wrong with the clocks
Speaker 2: we have now? I mean, my phone seems pretty accurate.
Speaker 2: The GPS on my car gets me to the grocery store.
Speaker 2: We have caesium clocks, strontium clocks. Why are scientists obsessed
Speaker 2: with making better clocks? Are we just splitting hairs at
Speaker 2: this point.
Speaker 3: It might seem like that, but for science and technology
Speaker 3: we are absolutely not splitting hairs. To answer that, we
Speaker 3: have to look at how we define time right now
Speaker 3: at the highest level, the level that governs GPS, the Internet,
Speaker 3: banking systems, and deep space navigation. We rely on optical atomic.
Speaker 2: Clocks, and these are the best we have.
Speaker 3: They are marvels of engineering. The latest strontium lattice clock,
Speaker 3: for instance, wouldn't lose or gain a second in about
Speaker 3: fifteen billion.
Speaker 2: Years, longer than the age of the universe exactly.
Speaker 3: So they are incredible, but they have some serious achilles heels.
Speaker 2: I've heard the term, but what is actually happening inside
Speaker 2: an atomic clock? It's not gears and springs, obviously.
Speaker 3: No, it's about energy levels and light. So let's look
Speaker 3: at a modern optical lattice clock. Imagine you have a
Speaker 3: vacuum chamber inside you trap thousands of atoms, usually strontium
Speaker 3: or yuterbium, using interfering laser beams.
Speaker 2: You're holding them with light.
Speaker 3: Holding them with light, were eating a shape like an
Speaker 3: egg crate. We call it an optical lattice. Each egg
Speaker 3: in the crate holds one atom, keeping them from bumping
Speaker 3: into each other and messing up the measurement.
Speaker 2: Okay, I've got my atoms. They are stuck in the
Speaker 2: egg crate.
Speaker 3: You cool them down, atom mean really cool. We use
Speaker 3: lasers to slow them down, a process called Doppler cooling
Speaker 3: to get them to microkelvin's barely above absolute zero. They're
Speaker 3: almost perfectly still.
Speaker 2: Okay, so we have frozen trapped atoms.
Speaker 3: Now what then you bring in the clock laser. This
Speaker 3: is a separate ultra stable laser tune too, a very
Speaker 3: specific frequency of light. You shine it on the atoms.
Speaker 3: If the frequency is exactly right, I mean exactly, it
Speaker 3: will excite the electrons in the atom to jump to
Speaker 3: a higher energy orbit.
Speaker 2: The quantum leap we were talking about the quantum leap.
Speaker 3: It's a very narrow resonance think of it like a
Speaker 3: key fitting a lock. Only one frequency will work. When
Speaker 3: you find that exact frequency that makes the jump happen,
Speaker 3: you know, okay, this frequency is our standard. You count
Speaker 3: the oscillations of that light. That is your tick.
Speaker 2: So the atom is the reference, it's the tuning for
Speaker 2: the laser is the bow playing the violin.
Speaker 3: That is a perfect analogy. The atom is the tuning fork,
Speaker 3: which is perfect and unchanging. The laser is the bow.
Speaker 3: But here is the problem with current technology.
Speaker 2: What's the problem.
Speaker 3: The ticked doesn't actually come from the atom. It comes
Speaker 3: from the laser. The laser is the thing generating the wave.
Speaker 3: We just use the atom to check if the laser
Speaker 3: is correct.
Speaker 2: So we're constantly asking the atom is this right? Is
Speaker 2: this right? Am I still on key?
Speaker 3: Yes, we lock the laser to the atom in a
Speaker 3: feedback loop. But lasers. Lasers are man made. They are imperfect.
Speaker 3: They have what we call phase noise. The mirrors in
Speaker 3: the laser cavity vibrate due to heat the electronics.
Speaker 2: Fluctuations, so the bow is shaky.
Speaker 3: The bow is shaky, and because the bow is shaky,
Speaker 3: we have to constantly correct it. This process creates a
Speaker 3: limit on stability. We are fighting a constant war against decoherence.
Speaker 3: What's that It's the laser noise scrambling the quantum information
Speaker 3: in the atoms. It's the external world messing up your
Speaker 3: perfect quantum state.
Speaker 2: And that limits how precise the clock can be.
Speaker 3: It limits the coherence time. Ideally, you want to interrogate
Speaker 3: the atom for a long time to get a precise measurement,
Speaker 3: but because the laser is noisy, you can't. You have
Speaker 3: to take short snapshots. It limits the ultimate precision.
Speaker 2: So the source material highlights these drawbacks. What are they specifically?
Speaker 3: Yes, it lists three big costs. First, complexity, these systems
Speaker 3: are absolute beasts. To manage you need vacuum chambers, multiple
Speaker 3: lasers for cooling, repumping, trapping, and the clock laser itself.
Speaker 3: It's a room full of equipment, so.
Speaker 2: You can't exactly wear one on your wrist or even
Speaker 2: put one in a small satellite easily.
Speaker 3: Definitely not. Second, they are fragile. They are incredibly sensitive
Speaker 3: to vibrations and temperature changes. If you shake them, the
Speaker 3: lattice breaks, the atoms fall out. And the third energy,
Speaker 3: and this is the big one for our discussion regarding
Speaker 3: the time crystal. To run an optical atomic clock, you
Speaker 3: are constantly blasting it with energy. You are driving the system.
Speaker 3: You are forcing the electrons up, they fall down, you
Speaker 3: push them.
Speaker 2: Up again, have to keep pushing the swing. If you
Speaker 2: stop pushing, the swinging stops.
Speaker 3: Exactly, you're constantly pumping energy into the system to force
Speaker 3: it to oscillate. This is an active system, and in
Speaker 3: quantum mechanics, active systems are prone to noise. The very
Speaker 3: act of pushing the atom disturbs it.
Speaker 2: So we have these amazing clocks, but they are energy hogs,
Speaker 2: They are fragile, and they only work because we are
Speaker 2: constantly bullying the atoms into keeping time.
Speaker 3: That's a very colorful way to put it, but yes,
Speaker 3: we are forcing order onto a chaotic system, and that
Speaker 3: brings us to Ludmilaviatti and her team.
Speaker 2: Enter the time crystal.
Speaker 3: Enter the time crystal.
Speaker 2: So the proposal from this news study published just this
Speaker 2: month February twenty twenty six is to throw out the
Speaker 2: idea of the bullied atom and replace it with a
Speaker 2: quantum time crystal clock.
Speaker 3: Right, And the core difference. The thing that makes this
Speaker 3: revolutionary is that a time crystal does not require that
Speaker 3: continuous energy intensive external excitation to sustain its oscillation in
Speaker 3: the same way.
Speaker 2: This goes back to what we said earlier. The rhythm
Speaker 2: is internal. It's not coming from a laser.
Speaker 3: Yes, the repeating pattern, the tick of the clock emerges
Speaker 3: from the intrinsic interactions within the system itself.
Speaker 2: I need an analogy because intrinsic interactions sounds like corporate
Speaker 2: speech for a team building exercise.
Speaker 3: Fair enough, Okay, think about the atomic clock the old way.
Speaker 3: Like a class of students trying to clap in unit
Speaker 3: in Okay, to get them to clap together, the teacher
Speaker 3: the laser has to stand at the front and conduct them. Clap, clap, clap.
Speaker 3: If the teacher stops, the students stop or fall out
Speaker 3: a rhythm.
Speaker 2: Okay, that's the external drive. Makes sense.
Speaker 3: Now, imagine a time crystal. The teacher leaves the room,
Speaker 3: but the students they hold hands. They're connected, they are entangled.
Speaker 3: They're quantum mechanically entangled. And because of the way they
Speaker 3: are connected, the specific physics of their interaction, a rhythm
Speaker 3: emerges from the group.
Speaker 2: So it's not imposed from the outside.
Speaker 3: Not at all. One student squeezes a hand, the next
Speaker 3: feels it and a wave of clapping propagates through the
Speaker 3: group and sustains itself. They keep the beat perfectly, not
Speaker 3: because someone is forcing them, but because the structure of
Speaker 3: their connection demands it.
Speaker 2: So the rhythm is a property of the collective, not
Speaker 2: the result of a conductor exactly.
Speaker 3: It provides a natural, built in rhythm. In physics terms,
Speaker 3: we say the system has a many body Hamiltonian that
Speaker 3: protects the coherence.
Speaker 2: Many body Hamiltonian. That sounds like a prog rock band.
Speaker 3: It does, but it essentially means. The math describing the
Speaker 3: energy of the system depends on all the particles interacting
Speaker 3: with each other, not just individually, and this interaction creates
Speaker 3: a stiffness or a rigidity in time.
Speaker 2: Rigidity is a good word, like how a diamond is
Speaker 2: rigid in space. You can't just push one atom out
Speaker 2: of place.
Speaker 3: Yes, that's a perfect way to think about it. If
Speaker 3: you try to bump one atom in a diamond, the
Speaker 3: bonds with this neighbors hold it in place. In a
Speaker 3: time crystal, if noise tries to bump the timing of
Speaker 3: one atom, the entanglement with its neighbors pulls it back
Speaker 3: into rhythm. It is self correcting.
Speaker 2: That is wild. So we are moving from a a
Speaker 2: high maintenance model to a self sustaining model.
Speaker 3: That is the hope, that's the promise of this whole idea.
Speaker 2: But how do you actually build a clock out of that?
Speaker 2: I mean, a circle of students holding hands is great,
Speaker 2: but the Audi's team isn't working with people. They're working
Speaker 2: with quantum particles. What did they do right?
Speaker 3: And this brings us to the simulation because to be clear,
Speaker 3: and I have to stress this, what this report details
Speaker 3: is a mathematical demonstration.
Speaker 2: They haven't built it yet.
Speaker 3: They have not built it. They simulated this engine on
Speaker 3: a powerful computer to see if it could actually keep
Speaker 3: time better than the conventional method.
Speaker 2: So let's look at the setup. What did they throw
Speaker 2: into the computer? What were the ingredients?
Speaker 3: They simulated an ensemble of one hundred quantum particles.
Speaker 2: Just one hundred. That seems low for something this revolutionary,
Speaker 2: you'd think.
Speaker 3: So, But in the quantum world, simulating one hundred interacting
Speaker 3: particles is actually a huge computational task. The complexity grows exponentially.
Speaker 3: The number of possible states is two to the power
Speaker 3: of one hundred, which is a number larger than the
Speaker 3: number of atoms in the earth.
Speaker 2: Okay, never mind, one hundred is a lot.
Speaker 3: You can't just run this on a laptop. They likely
Speaker 3: use sophisticated approximations like tensor networks to model it efficiently.
Speaker 2: Okay, fair enough, one hundred particles, and what are these
Speaker 2: particles doing.
Speaker 3: Each of these particles acts as a spin. You can
Speaker 3: think of it like a tiny magnet that can point up.
Speaker 2: Or down binary a quantum bit one or zero.
Speaker 3: Yes, but quantum so it can be a superposition of
Speaker 3: up and down at the same time. Now, they wanted
Speaker 3: to see if they could use this system to measure
Speaker 3: time using a technique called Ramsey interferometry.
Speaker 2: Ramsey interferometry, we need to define that. Is that standard practice.
Speaker 3: It's the gold standard way we measure time in quantum mechanics.
Speaker 3: It's a three step dance.
Speaker 2: Okay, let's hear the steps.
Speaker 3: Step one, you hit all the atoms with a quick
Speaker 3: pulse of microwave or laser radiation to put them in
Speaker 3: a superposition. Get them all spinning perfectly synchronized.
Speaker 2: Like spinning a top. One hundred tops all starting at
Speaker 2: the same time.
Speaker 3: Step two, you wait, this is the interrogation time. You
Speaker 3: let the atoms evolve freely. You let them tick. This
Speaker 3: is where the clock is actually running.
Speaker 2: Okay, so you just let them do their thing.
Speaker 3: Step three, you hit them with a second identical pulse
Speaker 3: to reout their state. This second pulse essentially stops the
Speaker 3: clock and allows you to measure how much their collective
Speaker 3: state has changed. By comparing the state at the end
Speaker 3: to the start, you know exactly how much time has passed.
Speaker 2: Got it. Pulse wait, pulse, measure the difference.
Speaker 3: Now in the simulation, they compare two different phases. This
Speaker 3: is the showdown part of the study.
Speaker 2: Phase one versus phase two, the old versus the new.
Speaker 3: Phase one is the conventional phase. In this simulation, they
Speaker 3: set up the particles so they would behave like a
Speaker 3: normal atomic clock. The particles were independent, They didn't talk
Speaker 3: to each other. They just evolved on their.
Speaker 2: Own, the lonely drummer phase, each one trying to keep
Speaker 2: its own beat right.
Speaker 3: And then they tried to measure time. Specifically, they looked
Speaker 3: at the stability of the clock, the precision. As they
Speaker 3: increased the interrogation time that weight period and what happened
Speaker 3: It hit the standard quantum limit. Basically, as time went on,
Speaker 3: small noises. Tiny fluctuations in the environment caused the atoms
Speaker 3: to dephase. They lost their synchronization.
Speaker 2: They started drifting.
Speaker 3: They started drifting, the signal got blurry. The precision degraded rapidly.
Speaker 3: If you imagine those hundred spinning tops, they all start
Speaker 3: spinning together. But after a while, summer a little faster,
Speaker 3: summer a little slower, and the whole thing is a mess.
Speaker 2: So the clock loses track of time if you wait
Speaker 2: too long.
Speaker 3: Exactly. Then they switched the simulation to phase two, the
Speaker 3: time crystalline.
Speaker 2: Phase, the entangled orchestra.
Speaker 3: They turned on the interactions. They set the parameters of
Speaker 3: the simulation so that the particles were strongly coupled to
Speaker 3: each other. They created that stiffness we talked about. They
Speaker 3: made the students hold.
Speaker 2: Hands, so now the tops are all connected by invisible strings.
Speaker 3: A great way to put it. And they ran the
Speaker 3: exact same Ramsey sequence pulse, wait, pulse, and the result.
Speaker 3: As a result, the precision remained far more robust. The
Speaker 3: graph I'm looking at Fig. Three in the paper mentally
Speaker 3: right now, shows that the variance, which is the measure
Speaker 3: of error, stayed flat for a much much longer time
Speaker 3: than in the conventional case.
Speaker 2: So the orchestra stayed in sync perfectly.
Speaker 3: The intrinsic interactions protected the phase of the clock. The
Speaker 3: entanglent thought off the decoherence from the environment.
Speaker 2: Here's where it gets really interesting for me, because usually
Speaker 2: in engineering, if you want more control, you add more control.
Speaker 2: You add more sensors, more feedback loops, more.
Speaker 3: Power, right, the brute force approach.
Speaker 2: But this result suggests that if you want the ultimate precision,
Speaker 2: you actually have to let go. You have to stop
Speaker 2: forcing the system and let it find its own stability
Speaker 2: through internal connection.
Speaker 3: That is a profound observation, and it's absolutely true. The
Speaker 3: stability of the time crystal comes from the fact that
Speaker 3: it is a many body system. It distributes the information
Speaker 3: of the time across all one hundred particles.
Speaker 2: It sounds like distributed computing or a blockchain. Almost the
Speaker 2: record isn't in one place, it's everywhere, so it's harder
Speaker 2: to corrupt.
Speaker 3: Very similar logic. If one particle gets knocked out a
Speaker 3: rhythm by a bit of noise, the other ninety nine
Speaker 3: pull it back in line. We call this Heisenberg limited scaling,
Speaker 3: or something close to it. It beats the standard quantum
Speaker 3: limit because the particles are acting as a single giant
Speaker 3: quantum object rather than one hundred small ones.
Speaker 2: So we have a simulation that says, hey, this weird
Speaker 2: state of matter we found ten years ago. It actually
Speaker 2: makes a better clock than the best technology we have today.
Speaker 3: In theory, yes, right, And specifically, it solves that external
Speaker 3: drive problem we talked about. Because the rhythm is internal.
Speaker 3: You don't need a nowsy laser to constantly drive the beat.
Speaker 3: You just need to initialize it and let it run.
Speaker 3: It's a passive clock.
Speaker 2: So yeah, what does this mean? Why should the listener care?
Speaker 2: I mean, I love a good clock, but I'm rarely
Speaker 2: late to meetings because my phone drifted by a nanosecond.
Speaker 2: This feels very esoteric.
Speaker 3: No, for you and me getting coffee, this doesn't matter.
Speaker 3: You will never need a time crystal to catch the bus.
Speaker 3: But for civilization, for our entire technology infrastructure, it matters
Speaker 3: a lot.
Speaker 2: Connect the dots. For us, where do we use clocks
Speaker 2: that need to be this good?
Speaker 3: The most obvious application is navigation. We all rely on
Speaker 3: GPS every single day.
Speaker 2: Which works by satellites sending timestamps.
Speaker 3: Yes, your phone listens for signals from multiple satellites. Those
Speaker 3: satellites are basically just flying atomic clocks. They send a
Speaker 3: signal saying the time I sent this was exactly twelve
Speaker 3: point zero zero zero zero zero zero zero zero zero
Speaker 3: zero one. Your phone compares the arrival times of signals
Speaker 3: from four different satellites to figure out where you are
Speaker 3: in three dimensional.
Speaker 2: Space triangulation or I guess quadrangulation.
Speaker 3: Right, But the accuracy of that location depends entirely on
Speaker 3: the accuracy of the clocks. Light travels very fast, about
Speaker 3: one foot per nanosecond a foot per nanosecond, so if
Speaker 3: the clock on the satellite is off by just a
Speaker 3: few nanoseconds, the error in your position could be several feet.
Speaker 2: So if the clock drifts, my GPS thinks I'm driving
Speaker 2: in the river instead of on.
Speaker 3: The bridge exactly Now, for your car, an error of
Speaker 3: a few feet is fine, but imagine a world of
Speaker 3: autonomous vehicles, drones delivering packages, and a growded city flying taxis.
Speaker 3: They need to know where they are within inches, not feet,
Speaker 3: and they need to know it instantly without fail.
Speaker 2: So we need better clocks in space, more stable clocks.
Speaker 3: And we need them to be stable, robust, and low power. Remember,
Speaker 3: current atomic clocks are fragile and power hungry. If we
Speaker 3: can build a time crystal clock, it could be smaller,
Speaker 3: require less power because it's self sustaining, and be more
Speaker 3: robust against the harsh radiation and vibration environment of space.
Speaker 2: That makes sense better GPS, safer self driving cars. But
Speaker 2: the report also mentions sensors. That seems like a different application.
Speaker 3: Entirely it is, but it's based on the same principle
Speaker 3: of stability. The source specifically mentions ultrasensitive detectors of magnetic fields.
Speaker 3: This is magnetometry.
Speaker 2: How does a clock detect a magnetic field?
Speaker 3: Well, remember that these particles are spins. They are essentially
Speaker 3: tiny magnets. The rhythm of the time crystal, the frequency
Speaker 3: of its oscillation, depends on the magnetic environment. It's in
Speaker 3: oh I see if an external magnetic field is present,
Speaker 3: it slightly alters the energy levels of the spins, which
Speaker 3: in turn changes the ticking rate of the clock in
Speaker 3: a very precise, predictable way.
Speaker 2: So it's a sensor. You measure the change in the
Speaker 2: ticking to measure the field.
Speaker 3: A quantum sensor. And because the time crystal is so
Speaker 3: stable against random noise, it becomes incredibly sensitive to specific
Speaker 3: signals like a magnetic field. It's like having a perfectly
Speaker 3: silent room where you can hear even the quietest whisper.
Speaker 2: What would we use that for?
Speaker 3: Everything from mineral exploration finding deposits of ore underground without digging,
Speaker 3: to non invasive medical imaging brain imaging. Your brain works
Speaker 3: by firing neurons. Those electrical currents create tiny, tiny magnetic fields. Currently,
Speaker 3: we use meg machines to detect them, but they are huge,
Speaker 3: they're expensive, and they require liquid helium cooling. A time
Speaker 3: crystal sensor could theoretically be a small room temperare device
Speaker 3: that is far more sensitive, allowing us to map brain
Speaker 3: activity with unprecedented detail. Wow.
Speaker 2: Okay, so we're talking about a fundamental leap in sensing technology.
Speaker 2: It's not just about time, it's about measuring the invisible
Speaker 2: forces of the world with incredible precision.
Speaker 3: Yes, but and there is always a butt And as
Speaker 3: the skeptic here, you should be waiting for it.
Speaker 2: I was waiting for it. I've been looking at the
Speaker 2: time stamp of our discussion and realizing we haven't solved
Speaker 2: the world's problems yet. Can I go to the hardware
Speaker 2: store and buy a time crystal clock today.
Speaker 3: No, you absolutely cannot. You can't even buy one from
Speaker 3: a high tech lab.
Speaker 2: Yet, why not If the simulation works, why don't we
Speaker 2: have the device? It sounds like the blueprint is there.
Speaker 3: Because, as I mentioned, this study by Viati and her
Speaker 3: team is a mathematical demonstration. It is a simulation. They
Speaker 3: prove that the physics works on paper and in a
Speaker 3: computer model.
Speaker 2: There is a big difference between a computer model and
Speaker 2: a physical device, a huge difference.
Speaker 3: The report explicitly quotes that there is a long road
Speaker 3: to practical applications.
Speaker 2: What are the roadblocks? What stands between us and this
Speaker 2: quantum future?
Speaker 3: Well, think about the requirements. To make this work. You
Speaker 3: need to create an ensemble of one hundred or more
Speaker 3: particles that are perfectly controlled and strongly interacting, and you
Speaker 3: need to keep them coherent for a long time.
Speaker 2: We can do that with quantum computers, right, Yeah, Google
Speaker 2: and IBM are building chips with lots of quibits.
Speaker 3: They are, but those systems are still incredibly noisy and
Speaker 3: error prone. Keeping one hundred particles entangled and coherent for
Speaker 3: a long period of time is the holy grail of
Speaker 3: quantum computing. We are getting better at it, but we
Speaker 3: aren't there yet. The engineering challenges are immense.
Speaker 2: So the time crystal clock relies on the same tech
Speaker 2: as quantum computers largely.
Speaker 3: Yes, it needs trapped ion technology or Ryberg atoms. You
Speaker 3: need to isolate these particles in a vacuum, cool them
Speaker 3: to near absolute zero, and then use lasers to engineer
Speaker 3: the interactions so they talk to each other in just
Speaker 3: the right way to form the time crystal state.
Speaker 2: So we are still talking about a room full of
Speaker 2: lasers and vacuum pumps. It's not a chick been a
Speaker 2: phone yet for now.
Speaker 3: Yes, we're at the Wright Brothers glider stage of this technology.
Speaker 3: Actually no, we're at the wind Tuttle blueprint stage. We
Speaker 3: know the aerodynamics work, we know the math holds up.
Speaker 3: Now someone has to actually bend the wood and stitch
Speaker 3: the canvas.
Speaker 2: But the hope is that this paper is the spark
Speaker 2: that lights the fire.
Speaker 3: Exactly. The goal of publishing this in Physical Review letters
Speaker 3: is to get the experimentalists excited. VIATI is basically saying, hey,
Speaker 3: to all my friends in the labs, look what the
Speaker 3: math says. If you build this, it will work.
Speaker 2: Here's the recipe and knowing physicists, they will tig that dare.
Speaker 3: Oh absolutely, the race is on Now. There are labs
Speaker 3: in Boulder, in Maryland, in Innsbruck that are likely reading
Speaker 3: this paper this morning and thinking can we reconfigure our
Speaker 3: trap to run this protocol.
Speaker 2: It is fascinating to think about the timeline here. In
Speaker 2: twenty twelve, this was just a crazy idea in Frank
Speaker 2: Wilcheck's head that everyone laughed at.
Speaker 3: Right perpetual motion.
Speaker 2: In twenty sixteen we saw it in a lab and realized, okay,
Speaker 2: it's real. Now in twenty twenty six we have the
Speaker 2: blueprint for a machine that uses it.
Speaker 3: It's a wrap acceleration. Usually new states of matter take
Speaker 3: decades to go from discovery to application. Superconductivity took half
Speaker 3: a century. This might happen in fifteen or twenty years
Speaker 3: from discovery to a working device.
Speaker 2: It really is incredible. So let's synthesize this. We've covered
Speaker 2: symmetry breaking, we've bashed traditional atomic clocks, and we've built
Speaker 2: a virtual time crystal. What is the big takeaway for me?
Speaker 3: The takeaway is a shift in philosophy for centuries. Precision
Speaker 3: meant control, It meant applying force. It meant holding nature
Speaker 3: down and forcing it to be regular clockwork, gears, pendulums, lasers.
Speaker 2: We imposed order on the world. We beat the chaos
Speaker 2: into submission.
Speaker 3: Yes, but this new research suggests that the ultimate order,
Speaker 3: the ultimate precision, comes from surrendering control. It comes from
Speaker 3: creating the right conditions and then letting a system settle
Speaker 3: into its own natural quantum rhythm.
Speaker 2: Moving from systems we have to force to keep time
Speaker 2: to systems that keep time because.
Speaker 3: Of what they are beautifully put. It's a move from
Speaker 3: artificials to ability to intrinsic stability.
Speaker 2: It really changes how you look at a clock. It's
Speaker 2: not just a tool. It's a reflection of how we
Speaker 2: interact with the universe. Are we fighting it or are
Speaker 2: we dancing with it?
Speaker 3: And that leads to a final thought. I want to
Speaker 3: leave with the listener little something to moll over. What's
Speaker 3: that We are taught in school that the universe tends
Speaker 3: toward disorder? The second law of thermodynamics, entropy always increases.
Speaker 2: Things fall apart.
Speaker 3: Things fall apart. If you leave a house alone, it
Speaker 3: gets dusty. If you leave a clock alone, it stops
Speaker 3: and rusts.
Speaker 2: Right, chaos wins in the end.
Speaker 3: But here we have a system that, left to its
Speaker 3: own devices, without continuous external energy, finds a perfect repeating
Speaker 3: order in time. It doesn't decay into randomness, it locks
Speaker 3: into structure. So my question is, if we can create
Speaker 3: machines that have an intrinsic, self sustaining rhythm, does that
Speaker 3: change how we think about entropy and disorder.
Speaker 2: Are we looking at a future where the most precise
Speaker 2: measurement of time comes from letting nature do its own thing,
Speaker 2: rather than for it with a laser.
Speaker 3: I think we are, And I think that suggests that
Speaker 3: order might be a more fundamental, more resilient property of
Speaker 3: the universe than we give it credit for. Maybe chaos
Speaker 3: doesn't always win.
Speaker 2: That is something to chew on while you are eating
Speaker 2: your Valentine's Day chocolates. Maybe order isn't something we have
Speaker 2: to build from scratch. Maybe it's waiting for us to
Speaker 2: just get out of the way.
Speaker 3: I like that thought.
Speaker 2: Thank you so much for joining us on this exploration
Speaker 2: of time crystals. If you want to dive deeper, and
Speaker 2: I mean really deep, like looking at the Hamiltonians yourself,
Speaker 2: check the show notes. We've linked the fizz dot org
Speaker 2: article and the references to the Vatti study and physical review.
Speaker 3: Letters definitely worth a read if you like the technical details.
Speaker 2: Until next time, stay curious.
Speaker 3: And keep watching the clock, or let the.
Speaker 2: Clock watch itself. By everyone