Agradecimentos: We thank Dieter Ehlers (University of Augsburg) for implementing fit functions in his Spektrolyst software package. This work was supported by FAPESP (SP-Brazil) Grants No. 2020/12283-0, No. 2018/11364-7, and No. 2017/10581-1; National Council of Scientific and Technological...

Agradecimentos: We thank Dieter Ehlers (University of Augsburg) for implementing fit functions in his Spektrolyst software package. This work was supported by FAPESP (SP-Brazil) Grants No. 2020/12283-0, No. 2018/11364-7, and No. 2017/10581-1; National Council of Scientific and Technological Development, CNPq Grants No. 309483/2018-2, No. 141026/2017-0, No. 442230/2014-1, and No. 304649/2013-9; CAPES Finance Code 001; and FINEP-Brazil and Brazilian Ministry of Science, Technology and Innovation. Z.F. acknowledges the funding from NSF-1708199. Work at Los Alamos National Laboratory (LANL) was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering

Abstract: The interplay between nontrivial topological states of matter and strong electronic correlations is one of the most compelling open questions in condensed matter physics. Due to experimental challenges, there is an increasing desire to find more microscopic techniques to complement the...

Abstract: The interplay between nontrivial topological states of matter and strong electronic correlations is one of the most compelling open questions in condensed matter physics. Due to experimental challenges, there is an increasing desire to find more microscopic techniques to complement the results of more traditional experiments. In this work, we locally explore the Kondo insulator Sm1-xGdxB6 by means of electron spin resonance (ESR) of Gd3+ ions at low temperatures. Our analysis reveals that the Gd3+ ESR line shape shows an anomalous evolution as a function of temperature, wherein for highly dilute samples (x approximate to 0.0002) the Gd3+ ESR line shape changes from a localized ESR local moment character to a diffusive-like character. Upon manipulating the sample surface with a focused ion beam we demonstrate, in combination with electrical resistivity measurements, that the localized character of the Gd3+ ESR line shape is recovered by increasing the penetration of the microwave in the sample. This provides compelling evidence for the contribution of surface or near-surface excitations to the relaxation mechanism in the Gd3+ spin dynamics. Our work brings new insights into the importance of nontrivial surface excitations in ESR, opening new routes to be explored both theoretically and experimentally

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2017/10581-1; 2018/11364-7; 2020/12283-0

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

304649/2013-9; 442230/2014-1; 141026/2017-0; 309483/2018-2

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

001

FINANCIADORA DE ESTUDOS E PROJETOS - FINEP

Aberto