Abstract
We report the ultrafast optical pump-probe spectroscopy measurements on the single-crystal cerium films.Our experimental re-sults of temperature-dependent quasiparticle dynamics reveal development of the hybridization between localized f moments and conduction electrons,i.e.,evolving from fluctuating hybridization to collective hybridization.Exotic phonon renormaliza-tion is discovered to appear at the emerging temperature(T+)of fluctuating hybridization apart from its known presence at the coherent temperature(T*),and can hardly be explained by the mean-field theory.The quasiparticle relaxation at high temper-atures indicates coexistence of nonthermal electron-electron scattering and inelastic Kondo scattering,while its behavior at low temperatures suggests onset of a phase in the y-phase dominated film.We also extract the indirect gap below T*,representing the appearance of collective hybridization.Our findings provide novel information about the hybridization and phase evolution in the heavy fermion systems.
基金项目
国家重点研发计划(2022YFA1403000)
国家重点研发计划(2022YFA1402200)
国家自然科学基金(92365102)
国家自然科学基金(11974070)
国家自然科学基金(11734006)
国家自然科学基金(11925408)
国家自然科学基金(11921004)
国家自然科学基金(12004067)
国家自然科学基金(62027807)
国家自然科学基金(12174331)
Frontier Science Project of Dongguan(2019622101004)
维普
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