Probing the f-state configuration of URu2Si2 with U LIII-edge resonant x-ray absorption spectroscopy

[摘要] It has often been said that the most interesting physics occurs when competing interactions are of nearly the same magnitude. Such a situation is surely occurring at URu₂Si₂???s so-called ???hidden-order transition???, which garners its name from the missing entropy at a 17.5 K phase transition relative to that expected for a conventional antiferromagnetic phase transition, despite the presence of only a very small ordered magnetic moment. Despite this discrepancy being identified in 1985, the identification of the order parameter remains elusive, although progress toward understand- ing this transition has been steady since that time, and URu₂Si₂ remains an important research subject today. The work described provides measures of the 5f orbital occupancy and itinerancy using resonant x-ray emission spectroscopy (RXES) at the U L_III absorption edge and measuring U L_??1 emission that potentially acts as a dividing line between different classes of ???hidden-order??? theories.

[发布日期] 2015-09-05

[学科分类] 凝聚态物理

[关键词] ABSORPTION SPECTROSCOPY;F STATES;X-RAY SPECTROSCOPY;ENTROPY;EMISSION SPECTROSCOPY;ORDER PARAMETERS;PHASE TRANSFORMATIONS;ANTIFERROMAGNETISM;MAGNETIC MOMENTS;TEMPERATURE RANGE 0013-0065 K;URANIUM SILICIDES;RUTHENIUM SILICIDES