Unveiling the Hybridization Process in a Quantum Critical Ferromagnet by Ultrafast Optical Spectroscopy
| Autor: | K. Hu, Huiqiu Yuan, Z. X. Wei, Yong-Ju Zhang, Y. H. Pei, Yang Yang, Jingbo Qi, Ye Chen |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Condensed Matter - Materials Science Condensed matter physics Strongly Correlated Electrons (cond-mat.str-el) Phonon Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology Electron 021001 nanoscience & nanotechnology Coupling (probability) 01 natural sciences Condensed Matter - Strongly Correlated Electrons Ferromagnetism Heavy fermion 0103 physical sciences 010306 general physics 0210 nano-technology Spectroscopy Ultrashort pulse Quantum |
| DOI: | 10.48550/arxiv.2102.08572 |
| Popis: | We report the ultrafast optical pump-probe spectroscopy measurements on the recently discovered quantum critical ferromagnet ${\mathrm{CeRh}}_{6}{\mathrm{Ge}}_{4}$. Our experimental results reveal the two-stage development of the hybridization between localized $f$ moments and conduction electrons with lowering temperature, as evidenced by (1) the presence of hybridization fluctuation for temperatures from $\ensuremath{\sim}85\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ (${T}^{*}$) to $\ensuremath{\sim}140\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ (${T}^{\ifmmode\dagger\else\textdagger\fi{}}$), and (2) the emergence of collective hybridization below the coherence temperature, ${T}^{*}$, marked by the opening of an indirect gap of $2\mathrm{\ensuremath{\Delta}}\phantom{\rule{4pt}{0ex}}\ensuremath{\approx}12\phantom{\rule{0.16em}{0ex}}\mathrm{meV}$. We also observe three coherent phonon modes being softened anomalously below ${T}^{*}$, reflecting directly their coupling with the emergent coherent heavy electrons. Our findings establish the universal nature of fluctuation and coherence during the hybridization process in heavy fermion systems. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|