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Why More Qubits Create a Bigger Challenge · The Quark Side - Quantum Physics Podcast

• 0:01
  Speaker 1: Welcome to the quart Side Quantum Physics Podcast, an exploration
• 0:05
  Speaker 1: of the fundamental structure of reality where quantum laws govern matter, energy,
• 0:11
  Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
• 0:16
  Speaker 1: and understanding begins at the smallest scales.
• 0:27
  Speaker 2: Imagine a machine, right that's capable of mapping the optimal
• 0:31
  Speaker 2: global shipping routes for like every single cargo vessel on
• 0:35
  Speaker 2: Earth in just the blink of an eye.
• 0:37
  Speaker 3: Right, Or even a system that can accurately simulate the
• 0:40
  Speaker 3: complex behavior of chemical molecules, which you know, would let
• 0:44
  Speaker 3: us design bespoke life saving drugs from scratch.
• 0:48
  Speaker 2: Yeah, exactly, without those decades of just trial and error
• 0:51
  Speaker 2: in a lab. I mean, we are talking about computational
• 0:54
  Speaker 2: power that doesn't just iterate faster, but solves problems fundamentally differently,
• 0:59
  Speaker 2: and all.
• 0:59
  Speaker 3: While operating with this incredible energy efficiency.
• 1:02
  Speaker 2: Totally, this is the towering promise of quantum computing. But
• 1:05
  Speaker 2: as engineer's race to scale these systems up from experimental
• 1:09
  Speaker 2: prototypes to massive, world changing machines, they're hitting this bizarre roadblock,
• 1:14
  Speaker 2: very weird one. Yeah, it turns out this quirk of
• 1:16
  Speaker 2: microscopic physics threatens to literally physically freeze the computer's calculations.
• 1:21
  Speaker 2: And it doesn't freeze because of a memory leak or
• 1:24
  Speaker 2: like a cooling failure.
• 1:26
  Speaker 3: No, it freezes simply because the outside universe is looking at.
• 1:28
  Speaker 2: It, which is just wild to think about.
• 1:30
  Speaker 3: It really is. I mean, the very act of existing
• 1:33
  Speaker 3: in a physical environment becomes an existential threat to the
• 1:36
  Speaker 3: calculation itself. Because in our everyday experience, observation is.
• 1:40
  Speaker 2: Passive, right like watching paint dry.
• 1:42
  Speaker 3: Exactly, You watch a pot of water boil and your
• 1:45
  Speaker 3: gaze doesn't actually change the temperature of the water. But
• 1:48
  Speaker 3: in the quantum realm, observation is an active physical interference.
• 1:53
  Speaker 2: So today we are going to really get into the
• 1:55
  Speaker 2: mechanics of why adding more power like scaling up these
• 1:59
  Speaker 2: machines inherently makes them more fragile.
• 2:02
  Speaker 3: Yeah, it's a huge paradox.
• 2:04
  Speaker 2: We'll look at the math behind how this oddity, known
• 2:07
  Speaker 2: as the quantum Zeno effect brings these quantum states to
• 2:10
  Speaker 2: a screeching halt and will break down the incredibly clever
• 2:14
  Speaker 2: ways scientists are redesigning the hardware from the ground up
• 2:18
  Speaker 2: to fight back. It's going to be a fun one, definitely.
• 2:20
  Speaker 2: So to understand why computer would freeze just from being observed.
• 2:24
  Speaker 2: I think we have to look at the specific type
• 2:26
  Speaker 2: of architecture we're dealing with here, right, the adybatic quantum computer.
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  Speaker 3: Yeah, so the quantum landscape is broad, and there are
• 2:33
  Speaker 3: you know, several theoretical ways to build a quantum machine.
• 2:36
  Speaker 3: Some rely on discrete logic gates, like.
• 2:39
  Speaker 2: How normal classical computers work, right, but.
• 2:41
  Speaker 3: With quibbots exactly similar to classical computers. But the adiabatic approach, however,
• 2:46
  Speaker 3: relies on continuous evolution over time. It operates on this
• 2:51
  Speaker 3: very elegant principle, which is keeping the quibbits in their
• 2:54
  Speaker 3: ground state.
• 2:55
  Speaker 2: And the ground state is just what the absolute lowest
• 2:59
  Speaker 2: possible energy state a quantum system can occupy.
• 3:02
  Speaker 3: You nailed it. It's the baseline of calm, you know,
• 3:05
  Speaker 3: the system's most stable configuration.
• 3:07
  Speaker 2: So instead of feeding the computer a math formula and
• 3:10
  Speaker 2: asking it to just crunch the numbers step by step,
• 3:13
  Speaker 2: you take your complex problem, say finding the most efficient
• 3:17
  Speaker 2: route for a delivery truck across one hundred cities, and
• 3:19
  Speaker 2: you map it onto a physical environment.
• 3:21
  Speaker 3: Right, You essentially build a physical representation of the math.
• 3:24
  Speaker 2: Okay, so you translate the problem into an energy landscape
• 3:26
  Speaker 2: that literally surrounds those quibbits.
• 3:29
  Speaker 3: Yeah, you start by setting up this initial energy landscape
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  Speaker 3: where the ground state is known and it's very easy
• 3:35
  Speaker 3: to prepare. Every single quibut is just resting comfortably at
• 3:39
  Speaker 3: its lowest energy level, nice and relaxed exactly. Then the
• 3:43
  Speaker 3: computer gradually alters the magnetic or you know, electromagnetic field
• 3:47
  Speaker 3: surrounding the quibits, which actually changes the shape of that
• 3:50
  Speaker 3: energy landscape.
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  Speaker 2: So it's morphing it over time.
• 3:52
  Speaker 3: Yeah, it slowly morphs the initial simple landscape into a new,
• 3:57
  Speaker 3: highly complex landscape that perfectly represents it's your difficult optimization problem.
• 4:02
  Speaker 2: And the crucial variable there is the speed of the transition. Right,
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  Speaker 2: if you morph this landscape slowly enough, which is what
• 4:10
  Speaker 2: adiabatic actually means in physics.
• 4:12
  Speaker 3: Right, Yes, a process where the system adapts without gaining
• 4:14
  Speaker 3: or losing heat to the outside.
• 4:16
  Speaker 2: Right. So if it's slow enough, the quibbits will continuously adapt.
• 4:19
  Speaker 2: They just stay in the ground state the entire time.
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  Speaker 3: Because the environment is changing so gradually, the quibbits naturally
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  Speaker 3: seek the path of least resistance.
• 4:27
  Speaker 2: You just write it out, exactly.
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  Speaker 3: They constantly adjust their configuration to remain in that lowest
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  Speaker 3: possible energy state, and once the landscape shift is completely finished,
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  Speaker 3: the system comes to a rest.
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  Speaker 2: And then you just read the final physical state of
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  Speaker 2: the quibts and boom. That configuration directly encodes the solution
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  Speaker 2: to your problem.
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  Speaker 3: That's it, that's your answer.
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  Speaker 2: Okay. So to visualize this for you listening, imagine a
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  Speaker 2: marble resting at the bottom of a large smooth bowl.
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  Speaker 2: That marble sitting at the lowest point that represents your
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  Speaker 2: qubit in its ground state.
• 5:00
  Speaker 3: I love this analogy.
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  Speaker 2: Yeah, right now, imagine you slowly and like very smoothly,
• 5:06
  Speaker 2: start to push on the sides of the bowl, changing
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  Speaker 2: its contours, creating new dips.
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  Speaker 3: And ridges, just warping the shape of it.
• 5:12
  Speaker 2: Exactly. If you reshape the bowl gently enough, the marble
• 5:15
  Speaker 2: will effortlessly roll along, constantly finding the new lowest point
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  Speaker 2: as the bowl changes shape.
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  Speaker 3: It just naturally settles, right, And when.
• 5:22
  Speaker 2: You stop reshaping the bowl, the marble settles into its
• 5:25
  Speaker 2: final resting place. The exact location of that marble gives
• 5:29
  Speaker 2: you the answer.
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  Speaker 3: And you know, the beauty of that adiabatic process is
• 5:33
  Speaker 3: that it is remarkably robust in theory and highly adaptable
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  Speaker 3: in practice. It's totally hardware independent.
• 5:40
  Speaker 2: Wait really, so you don't even need a specific type
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  Speaker 2: of chip.
• 5:43
  Speaker 3: No, you can build that ball out of entirely different
• 5:46
  Speaker 3: physical systems. Like you might use solid state superconductors, which
• 5:50
  Speaker 3: are these microscopic loops of metal chilled until electrical resistance
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  Speaker 3: just completely vanishes.
• 5:56
  Speaker 2: Wow, okay, Or you.
• 5:57
  Speaker 3: Could use individual ions charged atoms suspended in a vacuum
• 6:03
  Speaker 3: using incredibly precise electromagnetic traps.
• 6:06
  Speaker 2: So they both use the exact same fundamental principle.
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  Speaker 3: Yes, the gentle continuous reshaping of the energy landscape, because
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  Speaker 3: you aren't trying to manually force the qubits through complex
• 6:16
  Speaker 3: logic gates one by one.
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  Speaker 2: You just letting physics do the heavy lifting by seeking
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  Speaker 2: the lowest energy state.
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  Speaker 3: Naturally precisely, which makes it seem like the most reliable
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  Speaker 3: path for scaling up.
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  Speaker 2: But and this is a big butt that scaling up
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  Speaker 2: is exactly where the math turns ruthless.
• 6:31
  Speaker 3: Oh, absolutely ruthless.
• 6:32
  Speaker 2: Because physicists have been modeling what happens when we try
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  Speaker 2: to take this adiabatic process and scale it up to
• 6:39
  Speaker 2: the thousands or millions of kubits needed to actually solve
• 6:43
  Speaker 2: these world changing.
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  Speaker 3: Problems and it's not looking good.
• 6:46
  Speaker 2: No, because they've realized that the very act of building
• 6:50
  Speaker 2: a larger machine fundamentally alters the structure of that energy
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  Speaker 2: landscape we just talked about.
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  Speaker 3: It alters it profoundly. To understand why scaling is such
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  Speaker 3: a vulnerability, we have to the mechanics of the energy
• 7:01
  Speaker 3: states themselves.
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  Speaker 2: Right, Because equibit isn't just a switch that is off
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  Speaker 2: or on like a zero or a one.
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  Speaker 3: No, it relies on superposition, meaning it exists in a
• 7:10
  Speaker 3: complex combination of both states simultaneously. And it also relies
• 7:15
  Speaker 3: on entanglement.
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  Speaker 2: That's the mechanical link where the state of one quibbot
• 7:19
  Speaker 2: instantly correlates with the state of another, right regardless of
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  Speaker 2: the physical distance between them.
• 7:24
  Speaker 3: Exactly. The interplay of superposition and entanglement creates this vast
• 7:28
  Speaker 3: multidimensional space where calculations.
• 7:30
  Speaker 2: Happen and the numbers just explode exponentially. I mean, two
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  Speaker 2: quibots give you four possible states. Ten quivits give you
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  Speaker 2: oneenty twenty four states.
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  Speaker 3: It ramps up incredibly fast.
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  Speaker 2: Yeah, by the time you link three hundred cubits together,
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  Speaker 2: you literally have more possible states than there are atoms
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  Speaker 2: in the observable universe.
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  Speaker 3: Which is mind blowing, and this exponential explosion of states
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  Speaker 3: is the core of the spiling problem. Every time you
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  Speaker 3: add a quibit, you are doubling the number of possible
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  Speaker 3: energy levels in your system.
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  Speaker 2: But the total physical energy bandwidth of your machine, like
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  Speaker 2: the physical constraints of the circuits or the ion traps,
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  Speaker 2: does not scale infinitely.
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  Speaker 3: Right, You are cramming an exponentially growing number of energy
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  Speaker 3: states into a finite amount of physical space.
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  Speaker 2: Which means the distance between those states' shrinks exactly. So,
• 8:18
  Speaker 2: if we go back to the bowl and marble analogy,
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  Speaker 2: a small quantum computer with just a few quibits has
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  Speaker 2: a landscape with a nice, deep, steep valley. Right.
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  Speaker 3: Yes, the marble rests super securely at the bottom.
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  Speaker 2: But as you add hundreds of quibits, you're adding millions
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  Speaker 2: of new topological features to that exact same bowl. The
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  Speaker 2: landscape becomes incredibly complex, and the valley representing the ground
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  Speaker 2: state becomes vastly shallower.
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  Speaker 3: The energy gap, which is the mathematical difference between the
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  Speaker 3: ground state and the very next level up called the
• 8:48
  Speaker 3: first excited state, becomes infinitesimally small.
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  Speaker 2: So the required changes to the energy landscape become microscopically fine.
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  Speaker 3: Yeah, when you have a small machine with a deep
• 8:58
  Speaker 3: energy gap, a y disturbance from the outside world really
• 9:02
  Speaker 3: doesn't matter. I mean, the marble might jiggle a bit,
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  Speaker 3: but it stays in the deep valley.
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  Speaker 2: But in a scaled up machine with shallow valleys, the
• 9:09
  Speaker 2: marget for error effectively.
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  Speaker 3: Vanishes, completely vanishes.
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  Speaker 2: Yeah, okay, here is the pushback though. These machines are
• 9:15
  Speaker 2: housed in dilution refrigerators that cool the processors down to
• 9:19
  Speaker 2: what fifteen millikelvin?
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  Speaker 3: Yeah, we are talking a fraction of a degree above
• 9:23
  Speaker 3: absolute zero, which.
• 9:24
  Speaker 2: Is colder than the vacuum of deep space, and they're
• 9:26
  Speaker 2: buried inside layers of gold plated copper shielding to block
• 9:30
  Speaker 2: electromagnetic radiation.
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  Speaker 3: They are heavily protected.
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  Speaker 2: Yes, So if the system is essentially frozen and locked
• 9:36
  Speaker 2: in a high tech fault, why does a shallow energy
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  Speaker 2: gap even matter? Like what is actually getting inside to
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  Speaker 2: bump the marble out of the valley?
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  Speaker 3: Well, the harsh reality of thermodynamics is that absolute zero
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  Speaker 3: is just a theoretical limit. It can never be physically reached.
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  Speaker 2: So perfect isolation is a physical impossibility.
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  Speaker 3: Exactly No matter how many layers of shielding you use,
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  Speaker 3: or you know how powerful your cryogenics are, the universe
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  Speaker 3: is just a chaotic, noisy place.
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  Speaker 2: Something always gets through.
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  Speaker 3: A stray photon of microwave radiation from the wires themselves,
• 10:09
  Speaker 3: a microscopic fluctuation in the Earth's magnetic field, or even
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  Speaker 3: the faintest vibration of thermal energy will eventually leak into
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  Speaker 3: the chamber.
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  Speaker 2: And because the energy gap in a scaled up machine
• 10:19
  Speaker 2: is so impossibly tiny, an ambient thermal kick that wouldn't
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  Speaker 2: even register on a thermometer contains like more than enough
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  Speaker 2: energy to knock the quibit out of its ground state.
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  Speaker 3: Right throws the system into an excited state, totally ruining
• 10:32
  Speaker 3: the calculation. But you know, the problem goes even deeper
• 10:35
  Speaker 3: than just a physical bump. The real threat is how
• 10:38
  Speaker 3: quantum mechanics deals with these tiny incrusions.
• 10:40
  Speaker 2: Oh, this is a measurement thing.
• 10:42
  Speaker 3: Yes, any interaction between the quantum system and the outside
• 10:46
  Speaker 3: classical environment constitutes a measurement.
• 10:48
  Speaker 2: We really need to define measurement here because I feel
• 10:51
  Speaker 2: like it trips up a lot of people. It doesn't
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  Speaker 2: mean a scientist in a lab code is looking through
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  Speaker 2: a microscope.
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  Speaker 3: Right, No, not at all. In quantum mechanics, a measurement
• 11:00
  Speaker 3: is simply the transfer of information.
• 11:02
  Speaker 2: Okay, So if a stray photon hits a quibbit and
• 11:05
  Speaker 2: bounces off, the state of the photon is now correlated
• 11:09
  Speaker 2: with the state of equibot exactly.
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  Speaker 3: Information about the quibbet has leaked into the environment.
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  Speaker 2: The universe has essentially observed the system it has.
• 11:17
  Speaker 3: And the fundamental rule of quantum mechanics is that when
• 11:19
  Speaker 3: a system in a state of superposition is measured, it
• 11:23
  Speaker 3: is forced to pick a definite state.
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  Speaker 2: It collapses.
• 11:26
  Speaker 3: It collapses, it loses all its quantum properties and just
• 11:28
  Speaker 3: becomes a classical bit of information.
• 11:30
  Speaker 2: Which triggers the quantum Zeno effect.
• 11:32
  Speaker 3: Yes, the Zeno effect, and this is named.
• 11:34
  Speaker 2: After Zeno of Ilia, Right, Yeah, ancient Greek philosopher who
• 11:38
  Speaker 2: came up with the aero paradox.
• 11:40
  Speaker 3: That's the one. He argued that if you look at
• 11:42
  Speaker 3: an arrow in flight, at any single frozen instant of time,
• 11:46
  Speaker 3: the arrow is motionless.
• 11:48
  Speaker 2: Right, And if time is just a series of those
• 11:50
  Speaker 2: motionless instants, motion itself must be an illusion.
• 11:53
  Speaker 3: It's a trip. And in quantum physics this paradox becomes
• 11:58
  Speaker 3: literal reality.
• 11:59
  Speaker 2: Because if you continuously measure a quantum system, you prevent
• 12:03
  Speaker 2: its state from evolving.
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  Speaker 3: Exactly. Our eighty abattic computer relies on the continuous, smooth
• 12:08
  Speaker 3: evolution of the kibits as the energy landscape changes. Right,
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  Speaker 3: But every time the environment accidentally measures the system, like
• 12:16
  Speaker 3: every time a microscopic bit of heat or radiation leaks
• 12:19
  Speaker 3: in and forces a collapse, the natural evolution is interrupted.
• 12:22
  Speaker 2: The quibits are forced to pause, collapse into a definite state,
• 12:26
  Speaker 2: and then the system has to try to re establish
• 12:29
  Speaker 2: the quantum state and catch up to the changing landscape
• 12:32
  Speaker 2: all over again. It's totally like trying to bake a
• 12:34
  Speaker 2: highly sensitive soou.
• 12:35
  Speaker 3: Fle Oh, that's a good way to look at it.
• 12:37
  Speaker 2: Yeah, you put the batter in the oven, and the
• 12:39
  Speaker 2: heat needs to work its magic smoothly and continuously over
• 12:43
  Speaker 2: an hour for it to rise perfectly. Right. Yeah, but
• 12:45
  Speaker 2: the environment outside the oven is constantly interfering.
• 12:48
  Speaker 3: Right. It's like a hyperactive baker who just opens the
• 12:51
  Speaker 3: oven door every five seconds to check on the progress.
• 12:54
  Speaker 2: Exactly. Every time the door opens, cold air rushes in.
• 12:57
  Speaker 2: The delicate rising process halts, and the sufla collapses slightly.
• 13:01
  Speaker 2: If the environment opens that door constantly, the sufle never
• 13:04
  Speaker 2: rises at all.
• 13:05
  Speaker 3: And because the scaled up quantum computer has such shallow
• 13:09
  Speaker 3: energy valleys, it is exponentially more sensitive to the baker
• 13:12
  Speaker 3: opening the door.
• 13:13
  Speaker 2: Even the tiniest crack lets in enough noise.
• 13:16
  Speaker 3: Yeah, enough noise to constitute a measurement. If the environment
• 13:19
  Speaker 3: is leaking in and measuring the system constantly, the qubits
• 13:22
  Speaker 3: are forced to pause over and over.
• 13:24
  Speaker 2: So the system's mathematical evolution just slows to a crawl.
• 13:28
  Speaker 3: Worse than that. In the theoretical models for massively scaled
• 13:31
  Speaker 3: idiopatic machines, the calculation simply grinds to a complete halt.
• 13:35
  Speaker 2: Oh wow.
• 13:36
  Speaker 3: The computer freeze is called entirely paralyzed by the ambient
• 13:39
  Speaker 3: noise of the universe.
• 13:40
  Speaker 2: Man. So, if perfect isolation is physically impossible due to
• 13:44
  Speaker 2: the laws of thermodynamics, and building a bigger machine inherently
• 13:47
  Speaker 2: makes it more vulnerable to this Zeno effect, it sounds
• 13:51
  Speaker 2: like scaling up is a dead end. Like, how do
• 13:53
  Speaker 2: we build a million quibot processor if physics dictates it
• 13:57
  Speaker 2: will just freeze the moment we turn it on.
• 13:59
  Speaker 3: Well, it requires there is a fundamental paradigm shift in
• 14:02
  Speaker 3: how quantum architects actually approach hardware.
• 14:04
  Speaker 2: Design, because for the past decade, much of the industry's
• 14:08
  Speaker 2: focus has just been on manufacturing more quobts.
• 14:10
  Speaker 3: Yeah, exactly. The strategy was always to build the massive
• 14:14
  Speaker 3: chip first and just figure out how to cool it later.
• 14:17
  Speaker 2: But the theoretical research mapping out this scaling flaw proves
• 14:20
  Speaker 2: that approach is basically mathematically doomed.
• 14:23
  Speaker 3: It is mitigation must be built into the very foundation
• 14:27
  Speaker 3: of the hardware, utilizing a dual approach.
• 14:30
  Speaker 2: Okay, what does that look like.
• 14:31
  Speaker 3: So you're aggressively pushing the limits of passive protection while
• 14:35
  Speaker 3: simultaneously integrating active defense mechanisms.
• 14:39
  Speaker 2: Okay, the passive protection seems straightforward, though probably incredibly difficult
• 14:43
  Speaker 2: to engineer. I mean building better refrigerators and better shielding.
• 14:47
  Speaker 3: Right, Yeah, using materials with higher isotopic purity to prevent
• 14:50
  Speaker 3: internal radiation, and isolating the vacuum chambers from even the
• 14:54
  Speaker 3: microscopic seismic vibrations of traffic outside the laboratory.
• 14:58
  Speaker 2: So you basically build a thicker, heavier vault.
• 15:01
  Speaker 3: Right, but recognizing that the vault will always eventually leak,
• 15:04
  Speaker 3: researchers are designing algorithms to actively fight the Zeno effect
• 15:09
  Speaker 3: in real time while the calculation is actually running.
• 15:12
  Speaker 2: That's the active defense.
• 15:13
  Speaker 3: Yes, And one of the primary techniques being modeled is
• 15:16
  Speaker 3: the spin echo method, which is a concept originally developed
• 15:20
  Speaker 3: in the field of nuclear magnetic resonance.
• 15:23
  Speaker 2: Spin echo. I mean it sounds like something you'd use
• 15:25
  Speaker 2: to balance a radar signal, but we are using it
• 15:27
  Speaker 2: to unmeasure the quibits. How exactly do you actively fight
• 15:32
  Speaker 2: a microscopic thermal fluctuation that you can't even see coming.
• 15:36
  Speaker 3: By understanding how that fluctuation affects the quibits and intentionally
• 15:40
  Speaker 3: reversing it. Okay, When the environment interacts with a group
• 15:43
  Speaker 3: of quibits, it causes a phenomenon called dephasing.
• 15:46
  Speaker 2: Dephasing, so the environmental noise causes some of the quibbitts
• 15:50
  Speaker 2: quantum phases to rotate slightly faster than they should.
• 15:53
  Speaker 3: Exactly, and others to rotate slightly slower. Over time, they
• 15:58
  Speaker 3: fall out of sync, the quantum information scrambles and the
• 16:00
  Speaker 3: state collapses. So the spin echo method involves firing incredibly precise,
• 16:06
  Speaker 3: coherent pulses of electromagnetic energy at the entire quibit array
• 16:10
  Speaker 3: at very specific intervals during the calculation.
• 16:13
  Speaker 2: And this pulse is called a pie pulse right, effectively
• 16:16
  Speaker 2: one hundred and eighty degree flip.
• 16:17
  Speaker 3: That's right.
• 16:18
  Speaker 2: So to visualize how this actively erases the environmental noise,
• 16:22
  Speaker 2: imagine a group of runners on a track. At the
• 16:25
  Speaker 2: starting gun. They all begin running, but the track is uneven,
• 16:30
  Speaker 2: and this unevenness represents the environmental noise.
• 16:32
  Speaker 3: I like where this is going.
• 16:34
  Speaker 2: Because of the bumps and headwinds, some runners naturally run
• 16:37
  Speaker 2: faster and some run slower, So after a few seconds
• 16:40
  Speaker 2: the pack is totally spread out. They are dephasing.
• 16:42
  Speaker 3: But then you fire the pie pulse. The whistle blows,
• 16:45
  Speaker 3: and every single runner is forced to immediately turn one
• 16:47
  Speaker 3: hundred and eighty degrees and run back toward the starting line.
• 16:50
  Speaker 2: And the genius is what happens next. The fast runners,
• 16:53
  Speaker 2: who had gotten the furthest ahead now have the longest
• 16:56
  Speaker 2: distance to cover to get back, and the slow runners
• 16:59
  Speaker 2: who were trailed behind have the shortest distance because they're
• 17:03
  Speaker 2: still running at their respective speeds dictated by the uneven track.
• 17:07
  Speaker 2: The fast runners perfectly catch up to the slow runners
• 17:11
  Speaker 2: at the exact moment they all cross the starting.
• 17:13
  Speaker 3: Line, they arrive at the exact same time, completely in sync.
• 17:17
  Speaker 2: That is so cool, it really is.
• 17:19
  Speaker 3: By flipping the quantum states, the spin echo method forces
• 17:22
  Speaker 3: the environmental noise to cancel itself out. The phase errors
• 17:26
  Speaker 3: accumulated during the first half of the interval are perfectly
• 17:29
  Speaker 3: unwound during the second half.
• 17:31
  Speaker 2: So you essentially trick the environment into erasing his own footprint. Yes,
• 17:35
  Speaker 2: it's like every time the universe cracks open the oven
• 17:38
  Speaker 2: door to ruin the soufle the smart oven blasts of
• 17:41
  Speaker 2: perfectly calibrated pulse of heat that neutralizes the incoming cold
• 17:46
  Speaker 2: air before the soufla even registers the temperature drop.
• 17:49
  Speaker 3: That is a perfect way to describe it. It's an
• 17:51
  Speaker 3: active decoupling from the environment. And what physicists are realizing
• 17:55
  Speaker 3: is that for adyabbatic quantum computing to survive the leap
• 17:59
  Speaker 3: from undreds of quibets to millions of quibits, these spin
• 18:03
  Speaker 3: echo pulses and other dynamic decoupling techniques they can't just
• 18:08
  Speaker 3: be software patches applied.
• 18:10
  Speaker 2: After the fact, right, They have to be baked in.
• 18:12
  Speaker 3: The physical timing and energy requirements of these pulses must
• 18:15
  Speaker 3: dictate the physical layout of the microscopic wires on the
• 18:19
  Speaker 3: chip itself.
• 18:20
  Speaker 2: So you can't just slap a larger processor into an
• 18:22
  Speaker 2: old refrigerator. The mitigation of the environment really has to
• 18:25
  Speaker 2: be intertwined with the computational math from day one.
• 18:28
  Speaker 3: Yes, if you design the chip without designing the active
• 18:32
  Speaker 3: defenses simultaneously, you are building a machine that is mathematically
• 18:36
  Speaker 3: guaranteed to freeze.
• 18:37
  Speaker 2: The engineering challenge is staggering. I mean, we are asking
• 18:40
  Speaker 2: physicists to maintain this impossibly delicate balance on a microscopic tightrope,
• 18:45
  Speaker 2: and the tightrope gets thinner, more afraid, and more sensitive
• 18:49
  Speaker 2: to the wind with every single step they take forward.
• 18:51
  Speaker 3: It really is a whole new ballgame. The journey to
• 18:53
  Speaker 3: quantum supremacy is fundamentally different from the classical computing revolution.
• 18:57
  Speaker 2: Yeah, because when we move from vacuum tubes to silicon transistors,
• 19:01
  Speaker 2: the physics was mostly on our side, right, Shrinking classical
• 19:04
  Speaker 2: components made them faster and more efficient, exactly.
• 19:07
  Speaker 3: But as we've seen today, scaling up a quantum machine
• 19:10
  Speaker 3: brings us face to face with an antagonistic universe.
• 19:14
  Speaker 2: The dream of world changing computational powerli like the ability
• 19:18
  Speaker 2: to simulate reality at the atomic level. Is totally bottlenecked
• 19:22
  Speaker 2: by the simple, unavoidable act of the universe constantly interrogating
• 19:26
  Speaker 2: our math.
• 19:27
  Speaker 3: We really have to completely reframe how we view the
• 19:30
  Speaker 3: physical environment of a computer. It is not just the
• 19:32
  Speaker 3: room where the hardware sits. In the quantum realm, the
• 19:35
  Speaker 3: surrounding universe acts as an aggressive, highly disruptive participant in
• 19:39
  Speaker 3: the software itself. It's a relentless observer that forces the
• 19:43
  Speaker 3: machine to physically alter its behavior just by existing nearby, Which.
• 19:47
  Speaker 2: Leads us with a truly fascinating concept to consider as
• 19:50
  Speaker 2: we move into this new technological era. I mean, we've
• 19:53
  Speaker 2: spent this entire time talking about the quantum Zeno effect
• 19:56
  Speaker 2: is a fatal flaw, right, This annoying quirk of physics
• 19:59
  Speaker 2: that altz progress.
• 20:00
  Speaker 3: Yeah, an absolute nightmare for engineers, and.
• 20:03
  Speaker 2: We're actively inventing complex spin echo techniques just to escape
• 20:08
  Speaker 2: its frozen grip. But what if we stopped fighting it?
• 20:11
  Speaker 3: Ah, that's an interesting thought, right.
• 20:13
  Speaker 2: If constantly measuring a quantum system forces its evolution to
• 20:17
  Speaker 2: freeze in place, could we use the environment as a tool.
• 20:21
  Speaker 3: Like weaponizing the observation exactly?
• 20:23
  Speaker 2: Imagine wanting to preserve a highly volatile quantum state, effectively
• 20:28
  Speaker 2: creating long term quantum memory. Instead of trying to isolate
• 20:32
  Speaker 2: the quibit, what if we intentionally bombarded it with constant
• 20:36
  Speaker 2: microscopic measurements.
• 20:37
  Speaker 3: Using the Zeno effect to just freeze the data in time.
• 20:40
  Speaker 2: Yeah, like a mosquito and amber. As we struggle to
• 20:43
  Speaker 2: hide our greatest technological secrets from the universe, we might
• 20:46
  Speaker 2: find that the ultimate way to master quantum mechanics isn't
• 20:48
  Speaker 2: to just shut the universe out.
• 20:50
  Speaker 3: But to figure out exactly when to invite it in
• 20:52
  Speaker 3: to take a look exactly.
• 20:54
  Speaker 2: So think about that next time you hear about the
• 20:56
  Speaker 2: quantum revolution.