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.
In organic molecules, an exciton is a particle bound pair of an electron (negative charge) and its hole (positive charge). They are held together by Coulombic attraction and can move within molecular assemblies. Singlet fission ...
Nanophysics
Nov 1, 2024
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Polaritons are coupled excitations of electromagnetic waves with either charged particles or vibrations in the atomic lattice of a given material. They are widely used in nanophotonics because of their ability to confine ...
Nanophysics
Oct 22, 2024
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Researchers at Freie Universität Berlin, University of Maryland and NIST, Google AI, and Abu Dhabi set out to robustly estimate the free Hamiltonian parameters of bosonic excitations in a superconducting quantum simulator. ...
A research group led by University of Tsukuba has observed the cooperative behavior of polaron quasiparticles formed by the collective interaction of electrons and lattice vibrations around color centers in diamond crystals.
Condensed Matter
Sep 27, 2024
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Scientists have made a significant leap in developing lasers that use sound waves instead of light. These phonon lasers hold promise for advancements in medical imaging, deep-sea exploration, and other areas.
Optics & Photonics
Sep 6, 2024
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180
Thousands of light particles can merge into a type of "super photon" under certain conditions. Researchers at the University of Bonn have now been able to use "tiny nano molds" to influence the design of this so-called Bose-Einstein ...
Condensed Matter
Sep 2, 2024
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209
When different quantum states combine, new collective states of matter can emerge. In the quantum realm, combining components such as atoms that possess quantum effects can give rise to macroscopic quantum states of matter, ...
Condensed Matter
Aug 29, 2024
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206
Bruno Uchoa, a professor of condensed matter physics, and Hong-yi Xie, a postdoctoral fellow in condensed matter physics at the University of Oklahoma, have published research in the journal Proceedings of the National Academy ...
Condensed Matter
Aug 27, 2024
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180
Scientists from the National University of Singapore (NUS) have shown that excitonic resonances and transitions between excitons can significantly increase the efficiency of generating entangled photon pairs. This could lead ...
Condensed Matter
Aug 19, 2024
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152
In solar cells and light-emitting diodes, maintaining the excited state kinetics of molecules against annihilation is a race against time. These systems need to strike a careful balance between different processes that lead ...
Optics & Photonics
Aug 7, 2024
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