Quasiparticles & collective excitations as a research area investigates emergent, effective degrees of freedom in many-body systems, where interactions among underlying microscopic constituents give rise to particle-like or mode-like entities such as phonons, magnons, polarons, excitons, and plasmons. This field focuses on formulating and analyzing low-energy effective theories, dispersion relations, lifetimes, and interaction vertices of these excitations using frameworks such as many-body perturbation theory, Green’s functions, field-theoretic methods, and numerical many-body techniques. It plays a central role in understanding transport, superconductivity, topological phases, and nonequilibrium dynamics in condensed matter, ultracold atomic systems, and related quantum materials.
Skyrmions are localized, particle-like excitations in materials that retain their structure due to topological constraints (i.e., restrictions arising from properties that remain unchanged under smooth deformations). These ...
Just as overlapping ripples on a pond can amplify or cancel each other out, waves of many kinds—including light, sound and atomic vibrations—can interfere with one another. At the quantum level, this kind of interference ...
Condensed Matter
Aug 11, 2025
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A joint research team from Japan has observed "heavy fermions," electrons with dramatically enhanced mass, exhibiting quantum entanglement governed by the Planckian time—the fundamental unit of time in quantum mechanics. ...
Condensed Matter
Aug 5, 2025
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The ultrafast placement of an electron in a polar liquid generates collective molecular vibrations in a spherical nano-volume. The vibrations change the diameter of this sphere periodically for more than 100 picoseconds.
Optics & Photonics
Aug 1, 2025
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For the first time, spin waves, also known as magnons, have been directly observed at the nanoscale. This breakthrough was made possible by combining a high–energy-resolution electron microscope with a theoretical method ...
General Physics
Jul 24, 2025
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Is it wizardry? Physicists at the University of Konstanz have succeeded in changing the properties of a material in a non-thermal way with the help of light and magnons. The new process is not only promising for information ...
Quantum Physics
Jul 16, 2025
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The quantum computing revolution draws ever nearer, but the need for a computer that makes correctable errors continues to hold it back.
Quantum Physics
Jul 14, 2025
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Caltech scientists have found a fast and efficient way to add up large numbers of Feynman diagrams, the simple drawings physicists use to represent particle interactions. The new method has already enabled the researchers ...
General Physics
Jul 10, 2025
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Excitons—bound pairs of electrons and an electron hole—are quasiparticles that can arise in solids. While so-called "bright" excitons emit light and are therefore accessible, dark excitons are optically inactive. As a result, ...
Optics & Photonics
Jul 9, 2025
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122
Researchers from the Faculty of Physics at the University of Warsaw and the University of British Columbia have described how a so-called lone spinon—an exotic quantum excitation that is a single unpaired spin—can arise in ...
Condensed Matter
Jul 7, 2025
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