Emergent Particles in Quantum Materials: From Known Particles to Higgs-like Quasiparticles

Video overview

Physicists pursue particles that compose the universe using three complementary strategies. First, combine known particles into new composites, like building with Legos. Second, smash particles at higher energies to reveal hidden constituents or create new ones via quantum fields. Third, place particles in new environments to generate emergent behaviors through collective quantum interactions. The talk highlights emergent phenomena in crystals and ultra-cold materials, including Higgs-like excitations, and contrasts them with fundamental particles discovered at colliders. It also emphasizes practical technologies that emerge from these materials and notes the support from EPICS and the Gordon and Betty Moore Foundation.

• Three particle discovery approaches: composites, high energy smashing, and emergent materials
• Emergent particles in materials are not fundamental but can be engineered
• Links to technology, electronics, and Higgs research
• Foundation support and scientific context

Introduction: three pathways to discovering particles

The video frames particle physics around three core strategies. The first is to take old particles we know and bind them to form new composite particles, a method familiar to chemists and biologists who build complex structures from simpler units, akin to Legos. The second strategy involves smashing particles together at increasingly higher energies to break them into constituents or to excite new particles from underlying quantum fields. This approach has historically yielded fundamental particles like quarks and the Higgs boson, though it often yields chaotic results with many known particles. The third strategy focuses on placing known particles into novel environments or arranging them in new ways so that collective quantum interactions give rise to emergent particle behaviors. These emergent phenomena can resemble fundamental particles in certain respects but are not themselves fundamental constituents of the universe.

Emergent phenomena in materials: what counts as a particle

The speaker highlights several examples from condensed matter physics, where the collective behavior of many interacting electrons in a material creates quasiparticles or emergent particles. In some crystals, charge carriers behave as holes rather than electrons. In ultra-cold regimes, electrons pair up and move with essentially zero resistance, acting like new bound states. In metals cooled to low temperatures, electrons can acquire very high effective masses, and in two dimensional electron systems under specific magnetic and electric fields, excitations can carry fractional electric charge. In one dimension, electrons can split into separate excitations of charge and spin. There are also claims of emergent Higgs-like excitations in superfluid helium, long before a Higgs boson was observed as a fundamental particle at the Large Hadron Collider (LHC).

The Higgs contrast: fundamental vs emergent

The video contrasts emergent Higgs-like phenomena found in materials with the Higgs boson discovered at the LHC by smashing protons together. The key difference is that emergent Higgs bosons are collective phenomena arising from many-body systems, not fundamental constituents of reality. The emergent particles are valuable not as fundamental building blocks of the universe but as useful descriptions of complex material behavior that can be harnessed in technologies.

Technological relevance and the EPICS connection

Beyond curiosity, materials that host emergent particles have wide practical applications in electronics, computer chips, and future transport technologies such as levitating or high-speed trains. They also underpin the magnets and detectors used in high energy physics experiments like Higgs searches. The video notes that discovery and curation of emergent phenomena can be pursued actively by designing new materials. The funding and organizational support for this work come from initiatives like Gordon and Betty Moore Foundation's Emergent Phenomena in Quantum Systems (EPICS), which aims to drive discovery-driven research in novel electronic materials and transformative principles of complex matter. Viewers are encouraged to learn more via moore.org and the Moore Foundation’s social channels.