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.
New research from the Department of Energy's Oak Ridge National Laboratory, in collaboration with The Ohio State University and Amphenol Corporation, challenges conventional understanding about controlling heat flow in solid ...
Condensed Matter
Mar 5, 2026
1
67
Physicists in China have uncovered new evidence that chiral phonons and magnons can interact strongly inside magnetic crystals. Using neutron spectroscopy, a team led by Song Bao at Nanjing University mapped magnetic signatures ...
Physicists in China have unveiled new clues to the origins of high-temperature superconductivity in an iron-based material just a single unit-cell thick. Led by Qi-Kun Xue and Lili Wang at Tsinghua University, the team's ...
The world is never really at rest. Even in a vacuum near ultracold temperatures where all classical motion should come to a halt, you'll find quantum fluctuations. In thin, two-dimensional materials, these include random ...
Superconductivity
Feb 26, 2026
0
494
Scientists have observed a new microscopic mechanism enabling precise control of the magneto-optical properties of excitons in alloys of two-dimensional semiconductors. This discovery opens up tangible prospects for technological ...
Condensed Matter
Feb 23, 2026
0
49
Acoustic frequency combs organize sound or mechanical vibrations into a series of evenly spaced frequencies, much like the teeth on a comb. They are the acoustic counterparts of optical frequency combs, which consist of equally ...
Optics & Photonics
Feb 20, 2026
0
69
An Osaka Metropolitan University-led research team investigated the decay time of coherent longitudinal optical (LO) phonons both in a GaAs1−xNx epilayer and in a GaAs single crystal to clarify the effects of dilute nitridation.
General Physics
Feb 19, 2026
0
13
For the first time, researchers in China have accurately quantified how chaos increases in a quantum many-body system as it evolves over time. Combining experiments and theory, a team led by Yu-Chen Li at the University of ...
Adjusting the size and chemistry of nanocrystals within an ultrathin surface can speed up light-driven chemical reactions, according to a University of Michigan Engineering study published in the Journal of the American Chemical ...
Nanophysics
Feb 17, 2026
0
24
When light passes through materials, it typically changes direction and bends in predictable ways. This change in direction, known as refraction, is caused by a change in the speed of light as it enters a new medium. In some ...
