Amazing and exciting stuff! Unfortunately, this stuff is not easy to grasp for a layperson like me.
The scientists themselves call it "exotic physics" and it is about "collective excitations"!
"A team of scientists ... have presented the first experimental evidence of collective excitations with spin called chiral graviton modes (CGMs) in a semiconducting material. ..."
"Experiments on a quantum material have revealed for the first time what might be a particle similar to the hypothetical graviton particle. This elementary particle could be the missing link between Einstein’s theory of general relativity, which explains gravity, and quantum mechanics. ...
When matter interacts with these fields in particular ways, it causes “excitations” in the force fields which leads to energy being translated in waves through the field. The force carriers are the ‘quantisation’ of this energy, according to quantum mechanics. ..."
From the abstract:
"Exotic physics could emerge from interplay between geometry and correlation. In fractional quantum Hall (FQH) states, novel collective excitations called chiral graviton modes (CGMs) are proposed as quanta of fluctuations of an internal quantum metric under a quantum geometry description. Such modes are condensed-matter analogues of gravitons that are hypothetical spin-2 bosons. They are characterized by polarized states with chirality of +2 or −2, and energy gaps coinciding with the fundamental neutral collective excitations (namely, magnetorotons) in the long-wavelength limit. However, CGMs remain experimentally inaccessible. Here we observe chiral spin-2 long-wavelength magnetorotons using inelastic scattering of circularly polarized lights, providing strong evidence for CGMs in FQH liquids. At filling factor v = 1/3, a gapped mode identified as the long-wavelength magnetoroton emerges under a specific polarization scheme corresponding to angular momentum S = −2, which persists at extremely long wavelength. Remarkably, the mode chirality remains −2 at v = 2/5 but becomes the opposite at v = 2/3 and 3/5. The modes have characteristic energies and sharp peaks with marked temperature and filling-factor dependence, corroborating the assignment of long-wavelength magnetorotons. The observations capture the essentials of CGMs and support the FQH geometrical description, paving the way to unveil rich physics of quantum metric effects in topological correlated systems."
Researchers Find First Experimental Evidence for a Graviton-like Particle in a Quantum Material (the original news release)
Evidence for chiral graviton modes in fractional quantum Hall liquids (no public access)
Graviton modes and inelastic light scattering
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