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  • Physicists love particlesand with good reasonalmost everything in the universe

  • is made up of particles, so the physicist’s approach to understanding the universe is

  • to understand the particles that make it up. If you want to discover and catalogue new

  • particles (which physicists do), here are three approaches you can take.

  • First, you can take old particles we already know stuff about and just stick them together

  • to build new *composite* particles. That’s what chemists and molecular biologists spend

  • a lot of their time doing, and it’s kind of like figuring out what you can build with

  • legos.

  • Second, you can smash old particles together with ever increasing violence, either hoping

  • to break an old particle apart into previously unknown constituents or to excite a new particle

  • into existence from the quantum fields that underly all reality. Sometimes this works

  • and the smashing reveals an entirely new *fundamental* building block of the universe like quarks

  • or the Higgs boson. But most of the time it just makes a big mess, an explosion of old

  • particles we already know about.

  • Third, you can put old particles in new environments so that they behave differently, or put old

  • particles together in new ways so that new particle-like behaviors emerge through their

  • *collective* quantum interactions.

  • For example, in certain crystals, the particles that move around are not electrons themselves

  • but in fact holes or gaps in a densely packed sea of electrons.

  • Or, when you make certain materials really really cold, free electrons in them stop acting

  • like electrons and team up in pairs to act like weird electron-only atoms that move around

  • with essentially no resistance.

  • Or when you make certain metals really cold, electrons in them start acting as if they

  • were 1000 times *heavier* than normal.

  • Or if you make a super thin essentially 2-dimensional sheet of gallium arsenide with a perpendicular

  • magnetic field and parallel electric field and make it really cold, electrons start behaving

  • as if they had an electric charge that’s a fraction of what they normally do.

  • Or if you force electrons into a special 1-dimensional line, the particles that move back and forth

  • along that line *look* like electrons, except separated so that some of them have the charge

  • of an electron but no spin, while others have the spin but no charge.

  • Or if you cool helium down super super cold, youll find emergent particles that behave

  • like higgs bosons! These emergent higgs bosons were first discovered in 1973, 40 years before

  • the higgs boson fundamental particle was discovered at the Large Hadron Collider by violently

  • smashing together protons.

  • Of course, the particles that emerge when you put collections of electrons together

  • in materials aren’t fundamental constituents of the universe, but theyre far more diverse

  • and bizarre and weird and cool. And unlike searching for fundamental particles where

  • you just have to wait and see what nature has in store, we can actively find and curate

  • new emergent particles simply by making different weird materials that allow their emergent

  • properties to come to life. Plus, materials with emergent particles have real and far-reaching

  • practical technological use: in electronics, computer chips, levitating high speed trains,

  • and even the magnets and detectors used to discover the higgs boson at the Large Hadron

  • Collider.

  • This video was supported in part by the Gordon and Betty Moore Foundation’s Emergent Phenomena

  • in Quantum Systems Initiative. EPiQS supports discovery-driven research on novel electronic

  • materials and aims to stimulate breakthroughs to fundamentally change our understanding

  • of the organizing principles of complex matter. To learn more, visit or follow the

  • Moore foundation on twitter.

Physicists love particlesand with good reasonalmost everything in the universe


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奇妙な新しい粒子を発見する方法|創発量子準粒子 (How To Discover Weird New Particles | Emergent Quantum Quasiparticles)

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    林宜悉 に公開 2021 年 01 月 14 日