Pump-probe reflectivity study of ultrafast dynamics of strongly correlated 5f electrons in UO2

被引：1

作者：

An, Yong Q. ^{[1
]}

Taylor, Antoinette J. ^{[1
]}

Durakiewicz, Tomasz ^{[2
]}

Rodriguez, George ^{[1
]}

机构：

[1] Los Alamos Natl Lab, Mat Phys & Applicat Div, Ctr Integrated Nanotechnol, POB 1663, Los Alamos, NM 87545 USA

[2] Los Alamos Natl Lab, Mat Phys & Applicat Div, Condensed Matter & Magnet Sci, Los Alamos, NM 87545 USA

来源：

INTERNATIONAL CONFERENCE ON STRONGLY CORRELATED ELECTRON SYSTEMS (SCES 2010) | 2011年 / 273卷

关键词：

URANIUM-DIOXIDE; PHOTOEMISSION; POLARON; PHONONS;

D O I：

10.1088/1742-6596/273/1/012144

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

5f electrons in the Mott insulator UO2 produce intriguing electronic states and dynamics, such as strong correlation and f-f excitations. We have performed femtosecond pump-probe reflectivity measurements on a single crystal UO2 at temperatures of 5-300 K to study the ultrafast dynamics of photoexcited 5f electrons. Laser pulses at 400 nm pump 5f electrons across the Mott gap, while those at 800 nm probe the pump-induced change of reflectivity. We find temperature-dependent excitation and relaxation processes and long-lived acoustic phonons, and extract picosecond risetimes and microsecond relaxation times at low temperatures. The observed slow relaxation is ascribed to the decay of Hubbard excitons formed by U3+-U5+ pairs.

引用

页数：4

共 13 条

[1] SMALL-POLARON HOPPING IN MOTT-INSULATING UO2 [J].