Sample-Dependent Dirac-Point Gap in MnBi2Te4 and Its Response to Applied Surface Charge: A Combined Photoemission and ab initio Study | Sciact - CRIS-system of Boreskov Institute of Catalysis

Sample-Dependent Dirac-Point Gap in MnBi2Te4 and Its Response to Applied Surface Charge: A Combined Photoemission and ab initio Study Full article

Journal

Physical Review B (started in 2016)
ISSN: 2469-9950 , E-ISSN: 2469-9969

Output data

Year: 2021, Volume: 104, Number: 11, Article number : 115168, Pages count : 11 DOI: 10.1103/physrevb.104.115168

Tags

Density functional theory; Photoelectron spectroscopy; Surface charge

Authors

Shikin A.M. ¹ , Estyunin D.A. ¹ , Zaitsev N.L. ² , Glazkova D. ¹ , Klimovskikh I.I. ¹ , Filnov S.O. ¹ , Rybkin A.G. ¹ , Schwier E.F. ³ , Kumar S. ³ , Kimura A. ⁴ , Mamedov N. ⁵ , Aliev Z. ^5,6 , Babanly M.B. ⁷ , Kokh K. ^1,8,17 , Tereshchenko O.E. ^1,9,10 , Otrokov M.M. ^11,12 , Chulkov E.V. ^1,13,14 , Zvezdin K.A. ^15,16 , Zvezdin A.K. ^15,16

Affiliations

1	Saint Petersburg State University, 198504 Saint Petersburg, Russia
2	Institute of Molecule and Crystal Physics, Ufa Federal Research Center of the Russian Academy of Sciences, 450075, Ufa, Russia
3	Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
4	Graduate School of Advanced Science and Engineering, Hiroshima University, Hiroshima 739-8526, Japan
5	Institute of Physics, ANAS, AZ1143 Baku, Azerbaijan
6	Azerbaijan State Oil and Industry University, AZ1010 Baku, Azerbaijan
7	Institute of Catalysis and Inorganic Chemistry, ANAS, AZ1143 Baku, Azerbaijan
8	V.S. Sobolev Institute of Geology and Mineralogy, Novosibirsk, 630090, Russia
9	A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, 630090, Russia
10	Novosibirsk State University, Novosibirsk, 630090, Russia
11	Centro de Física de Materiales, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián, Spain
12	IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao, Basque Country, Spain
13	Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
14	Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080 San Sebastián/Donostia, Basque Country, Spain
15	A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, 119991, Russia
16	Russian Quantum Center, Skolkovo, 143025, Russia
17	Kemerovo State University, Kemerovo, 650000, Russia

Recently discovered intrinsic antiferromagnetic topol. insulator MnBi2Te4 presents an exciting platform for realization of the quantum anomalous Hall effect and a number of related phenomena at elevated temperatures An important characteristic making this material attractive for applications is its predicted large magnetic gap at the Dirac point (DP). However, while the early exptl. measurements reported on large DP gaps, a number of recent studies claimed to observe a gapless dispersion of the MnBi2Te4 Dirac cone. Here, using micro(μ)-laser angle-resolved photoemission spectroscopy, we study the electronic structure of 15 different MnBi2Te4 samples, grown by two different chemists groups. Based on the careful energy distribution curves anal., the DP gaps between 15 and 65 meV are observed, as measured below the Néel temperature at about 10-16 K. At that, roughly half of the studied samples show the DP gap of about 30 meV, while for a quarter of the samples the gaps are in the 50 to 60 meV range. Summarizing the results of both our and other groups, in the currently available MnBi2Te4 samples the DP gap can acquire an arbitrary value between a few and several tens of meV. Furthermore, based on the d. functional theory, we discuss a possible factor that might contribute to the reduction of the DP gap size, which is the excess surface charge that can appear due to various defects in surface region. We demonstrate that the DP gap is influenced by the applied surface charge and even can be closed, which can be taken advantage of to tune the MnBi2Te4 DP gap size.

Shikin A.M. , Estyunin D.A. , Zaitsev N.L. , Glazkova D. , Klimovskikh I.I. , Filnov S.O. , Rybkin A.G. , Schwier E.F. , Kumar S. , Kimura A. , Mamedov N. , Aliev Z. , Babanly M.B. , Kokh K. , Tereshchenko O.E. , Otrokov M.M. , Chulkov E.V. , Zvezdin K.A. , Zvezdin A.K.
Sample-Dependent Dirac-Point Gap in MnBi2Te4 and Its Response to Applied Surface Charge: A Combined Photoemission and ab initio Study
Physical Review B (started in 2016). 2021. V.104. N11. 115168 :1-11. DOI: 10.1103/physrevb.104.115168 WOS Scopus AN OpenAlex

Submitted:	Jul 2, 2021
Accepted:	Sep 13, 2021
Published print:	Sep 15, 2021
Published online:	Sep 30, 2021

Web of science:	WOS:000704417000002
Scopus:	2-s2.0-85116321146
Chemical Abstracts:	2021:2277770
OpenAlex:	W3180218589

DB	Citing
Scopus	69
Web of science	66
OpenAlex	63