Year: 2026
Type: article
Abstract: Electronic phases in quantum materials are often governed by nanoscale inhomogeneity, where local order develops within spatially confined regions, or puddles. A prominent example is an incommensurate charge-density-wave (I-CDW) comprising locally commensurate domains. In 2H-NbSe2, such an I-CDW state persists alongside lattice anharmonicity and superconductivity, raising fundamental questions about the dynamical stabilization of CDW order in puddles. Here, using Raman scattering, we reveal a strong Fano-coupling between interlayer shear phonons and the CDW amplitude mode. Our time-resolved reflectivity measurement shows a low-frequency ∼0.2 THz coherent overdamped oscillation onsetting within the CDW regime at ∼17K, indicating a previously unexplored transition. This we identify as a Fano-coupled phonon-CDW hybrid emerging from the collective dynamics of CDW puddles. We establish an overdamped-oscillator framework for capturing such intertwined glassy dynamics. These results highlight how lattice pinning and electronic correlations shape CDW order in layered materials, insight crucial for designing novel van der Waals devices.
Source: Nano Letters
Authors: Shreya Kumbhakar, Marina Esposito, Anjan Kumar N M, Liwen Feng, Tommaso Confalone, Vasilisa Gerega, Flavia Lo Sardo, Rafiqul Alam, Davide Masarotti, Francesco Tafuri, Thomas Böhm, Mahmoud Abdel-Hafiez, Sushmita Chandra, Claudia Felser, Kornelius Nielsch, Nicola Poccia, Stefan Kaiser, Golam Haider
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1648780019, G2152757567, Fortschritte bei den Methoden zur Realisierung thermoelektrischer Schaltungen in verdrillten VanderWaalsHochtemperaturKupferheterostrukturen, G2292069225, AxionElektrodynamik von SupraleiterTopologischeIsolatorHeterostrukturen, G5443090575, G5473878947, G5989841040, EXC 2147: Komplexität und Topologie in Quantenmaterialien (CT.QMAT), Kontrolle starker Korrelationen von HochtemperaturSupraleitern mit VanderWaalsHeterostrukturen, Phase-resolved THz-Higgs Spectroscopy on Superconductors, 3D Cuprate Twistronics as a platform for high temperature topological superconductivity, SFB 1143: Korrelierter Magnetismus: Von Frustration zu Topologie, G936330020
OpenAlex ID: W7221526533