Dirac Gap Opening and Diracfermionmediated Magnetic Coupling in Antiferromagnetic GdDoped Topological Insulators and Their Manipulation by Synchrotron Radiation Научная публикация
Журнал 
Scientific Reports
, EISSN: 20452322 


Вых. Данные  Год: 2019, Том: 9, Номер: 1, Номер статьи : 4813, Страниц : 17 DOI: 10.1038/s4159801941137w  
Ключевые слова  Magnetic properties and materials; Quantum Hall; Topological insulators; Twodimensional materials  
Авторы 


Организации 

Реферат:
A new kind of magneticallydoped antiferromagnetic (AFM) topological insulators (TIs) with stoichiometry Bi1.09Gd0.06Sb0.85Te3 has been studied by angleresolved photoemission spectroscopy (ARPES), superconducting magnetometry (SQUID) and Xray magnetic circular dichroism (XMCD) with analysis of its electronic structure and surfacederived magnetic properties at different temperatures. This TI is characterized by the location of the Dirac gap at the Fermi level (EF) and a bulk AFM coupling below the Neel temperature (4–8 K). At temperatures higher than the bulk AFM/PM transition, a surface magnetic layer is proposed to develop, where the coupling between the magnetic moments located at magnetic impurities (Gd) is mediated by the Topological Surface State (TSS) via surface Diracfermionmediated magnetic coupling. This hypothesis is supported by a gap opening at the Dirac point (DP) indicated by the surfacesensitive ARPES, a weak hysteresis loop measured by SQUID at temperatures between 30 and 100 K, XMCD measurements demonstrating a surface magnetic moment at 70 K and a temperature dependence of the electrical resistance exhibiting a midgap semiconducting behavior up to temperatures of 100–130 K, which correlates with the temperature dependence of the surface magnetization and confirms the conclusion that only TSS are located at the EF. The increase of the TSS’s spectral weight during resonant ARPES at a photon energy corresponding to the Gd 4d4f edge support the hypothesis of a magnetic coupling between the Gd ions via the TSS and corresponding magnetic moment transfer at elevated temperatures. Finally, the observed outofplane and inplane magnetization induced by synchrotron radiation (SR) due to nonequal depopulation of the TSS with opposite momentum, as seen through change in the Dirac gap value and the k∥shift of the Dirac cone (DC) states, can be an indicator of the modification of the surface magnetic coupling mediated by the TSS.
Библиографическая ссылка:
Shikin A.M.
, Estyunin D.A.
, Surnin Y.I.
, Koroleva A.V.
, Shevchenko E.V.
, Kokh K.A.
, Tereshchenko O.E.
, Kumar S.
, Schwier E.F.
, Shimada K.
, Yoshikawa T.
, Saitoh Y.
, Takeda Y.
, Kimura A.
Dirac Gap Opening and Diracfermionmediated Magnetic Coupling in Antiferromagnetic GdDoped Topological Insulators and Their Manipulation by Synchrotron Radiation
Scientific Reports. 2019. V.9. N1. 4813 :117. DOI: 10.1038/s4159801941137w Scopus
Dirac Gap Opening and Diracfermionmediated Magnetic Coupling in Antiferromagnetic GdDoped Topological Insulators and Their Manipulation by Synchrotron Radiation
Scientific Reports. 2019. V.9. N1. 4813 :117. DOI: 10.1038/s4159801941137w Scopus
Даты:
Поступила в редакцию:  26 сент. 2018 г. 
Принята к публикации:  27 февр. 2019 г. 
Опубликована в печати:  18 мар. 2019 г. 
Опубликована online:  18 мар. 2019 г. 
Идентификаторы:
Scopus  2s2.085063030426 