Evolution of Mn1−xGexBi2Te4 Electronic Structure under Variation of Ge Content | Sciact - CRIS-система Института катализа

Evolution of Mn1−xGexBi2Te4 Electronic Structure under Variation of Ge Content Научная публикация

Журнал

Nanomaterials
, E-ISSN: 2079-4991

Вых. Данные

Год: 2023, Том: 13, Номер: 14, Номер статьи : 2151, Страниц : 13 DOI: 10.3390/nano13142151

Ключевые слова

magnetic topological insulator; topological surface states; electronic structure; topological phase transition; topological vertical heterostructure; ARPES; ab-initio calculations

Авторы

Estyunina Tatiana P. ¹ , Shikin Alexander M. ¹ , Estyunin Dmitry A. ¹ , Eryzhenkov Alexander V. ¹ , Klimovskikh Ilya I. ² , Bokai Kirill A. ¹ , Golyashov Vladimir A. ^1,3,4 , Kokh Konstantin A. ^1,5 , Tereshchenko Oleg E. ^1,3,4 , Kumar Shiv ⁶ , Shimada Kenya ⁶ , Tarasov Artem V. ¹

Организации

1	Department of Physics, Saint Petersburg State University, St. Petersburg 198504, Russia
2	Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain
3	Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol’tsovo 630559, Russia
4	Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
5	Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
6	Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan

One of the approaches to manipulate MnBi2Te4 properties is the magnetic dilution, which inevitably affects the interplay of magnetism and band topology in the system. In this work, we carried out angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations for analysing changes in the electronic structure of Mn1-xGexBi2Te4 that occur under parameter x variation. We consider two ways of Mn/Ge substitution: (i) bulk doping of the whole system; (ii) surface doping of the first septuple layer. For the case (i), the experimental results reveal a decrease in the value of the bulk band gap, which should be reversed by an increase when the Ge concentration reaches a certain value. Ab-initio calculations show that at Ge concentrations above 50%, there is an absence of the bulk band inversion of the Te pz and Bi pz contributions at the Γ-point with significant spatial redistribution of the states at the band gap edges into the bulk, suggesting topological phase transition in the system. For case (ii) of the vertical heterostructure Mn1-xGexBi2Te4/MnBi2Te4, it was shown that an increase of Ge concentration in the first septuple layer leads to effective modulation of the Dirac gap in the absence of significant topological surface states of spatial redistribution. The results obtained indicate that surface doping compares favorably compared to bulk doping as a method for the Dirac gap value modulation.

Estyunina T.P. , Shikin A.M. , Estyunin D.A. , Eryzhenkov A.V. , Klimovskikh I.I. , Bokai K.A. , Golyashov V.A. , Kokh K.A. , Tereshchenko O.E. , Kumar S. , Shimada K. , Tarasov A.V.
Evolution of Mn1−xGexBi2Te4 Electronic Structure under Variation of Ge Content
Nanomaterials. 2023. V.13. N14. 2151 :1-13. DOI: 10.3390/nano13142151 WOS Scopus CAPlus PMID OpenAlex СКИФ ID

Принята к публикации:	23 июл. 2023 г.
Опубликована в печати:	24 июл. 2023 г.
Опубликована online:	24 июл. 2023 г.
Поступила в редакцию:	30 июл. 2023 г.

Web of science:	WOS:001039657500001
Scopus:	2-s2.0-85166251765
Chemical Abstracts:	2023:1616288
PMID (PubMed):	37513162
OpenAlex:	W4385241043
СКИФ ID:	1549

БД	Цитирований
OpenAlex	11
Web of science	6
Scopus	8