_version_ 1866915110766772224
author Otrokov, Mikhail M.
Klimovskikh, Ilya I.
Bentmann, Hendrik
Estyunin, Dmitry
Zeugner, Alexander
Aliev, Ziya S.
Gass, Sebastian
Wolter, Anja U. B.
Koroleva, Alexandra V.
Shikin, Alexander M.
Blanco-Rey, María
Hoffmann, Martin
Rusinov, Igor P.
Vyazovskaya, Alexandra Yu.
Eremeev, Sergey V.
Koroteev, Yury M.
Kuznetsov, V. M.
Freyse, F.
Sánchez-Barriga, J.
Amiraslanov, Imamaddin R.
Babanly, Mahammad B.
Mamedov, Nazim T.
Abdullayev, Nadir A.
Zverev, Vladimir N.
Alfonsov, Alexey
Kataev, Vladislav
Büchner, Bernd
Schwier, Eike F.
Kumar, Shiv
Kimura, Akio
Petaccia, Luca
Di Santo, Giovanni
Vidal, Raphael C.
Schatz, Sonja
Kißner, Katharina
Ünzelmann, M.
Min, Chul-Hee
Moser, Simon K.
Peixoto, Thiago R. F.
Reinert, Friedrich
Ernst, Arthur
Echenique, Pedro M.
Isaeva, Anna
Chulkov, Evgueni V.
author_facet Otrokov, Mikhail M.
Klimovskikh, Ilya I.
Bentmann, Hendrik
Estyunin, Dmitry
Zeugner, Alexander
Aliev, Ziya S.
Gass, Sebastian
Wolter, Anja U. B.
Koroleva, Alexandra V.
Shikin, Alexander M.
Blanco-Rey, María
Hoffmann, Martin
Rusinov, Igor P.
Vyazovskaya, Alexandra Yu.
Eremeev, Sergey V.
Koroteev, Yury M.
Kuznetsov, V. M.
Freyse, F.
Sánchez-Barriga, J.
Amiraslanov, Imamaddin R.
Babanly, Mahammad B.
Mamedov, Nazim T.
Abdullayev, Nadir A.
Zverev, Vladimir N.
Alfonsov, Alexey
Kataev, Vladislav
Büchner, Bernd
Schwier, Eike F.
Kumar, Shiv
Kimura, Akio
Petaccia, Luca
Di Santo, Giovanni
Vidal, Raphael C.
Schatz, Sonja
Kißner, Katharina
Ünzelmann, M.
Min, Chul-Hee
Moser, Simon K.
Peixoto, Thiago R. F.
Reinert, Friedrich
Ernst, Arthur
Echenique, Pedro M.
Isaeva, Anna
Chulkov, Evgueni V.
contents Magnetic topological insulators (MTIs) are narrow gap semiconductor materials that combine non-trivial band topology and magnetic order. Unlike their nonmagnetic counterparts, MTIs may have some of the surfaces gapped due to breaking the time-reversal symmetry, which enables a number of exotic phenomena having potential applications in spintronics. So far, MTIs have only been created by means of doping nonmagnetic TIs with 3d transition metal elements, however, such an approach leads to strongly inhomogeneous magnetic and electronic properties of these materials, restricting the observation of important effects to very low temperatures. Finding intrinsic MTI, i.e. a stoichiometric well-ordered magnetic compound, could be an ideal solution to these problems, but no such material was observed to date. Here, using density functional theory we predict and further confirm by means of structural, transport, magnetic, angle- and spin-resolved photoemission spectroscopy measurements the realization of the antiferromagnetic (AFM) TI phase, that is hosted by the van der Waals layered compound MnBi$_2$Te$_4$. An interlayer AFM ordering makes MnBi$_2$Te$_4$ invariant with respect to the combination of the time-reversal ($Θ$) and primitive-lattice translation ($T_{1/2}$) symmetries, $S = ΘT_{1/2}$, giving rise to the $Z_2$ topological classification of AFM insulators. We find $Z_2 = 1$ for MnBi$_2$Te$_4$, which confirms its topologically nontrivial nature. The $S$-breaking (0001) surface of MnBi$_2$Te$_4$ exhibits a giant bandgap in the topological surface state as evidenced by ab initio calculations and photoemission measurements. These results culminate almost a decade-long search of an AFMTI, predicted in 2010. Furthermore, MnBi$_2$Te$_4$ is the first intrinsic magnetic TI realized experimentally.
format Preprint
id arxiv_https___arxiv_org_abs_1809_07389
institution arXiv
publishDate 2018
record_format arxiv
spellingShingle Prediction and observation of the first antiferromagnetic topological insulator
Otrokov, Mikhail M.
Klimovskikh, Ilya I.
Bentmann, Hendrik
Estyunin, Dmitry
Zeugner, Alexander
Aliev, Ziya S.
Gass, Sebastian
Wolter, Anja U. B.
Koroleva, Alexandra V.
Shikin, Alexander M.
Blanco-Rey, María
Hoffmann, Martin
Rusinov, Igor P.
Vyazovskaya, Alexandra Yu.
Eremeev, Sergey V.
Koroteev, Yury M.
Kuznetsov, V. M.
Freyse, F.
Sánchez-Barriga, J.
Amiraslanov, Imamaddin R.
Babanly, Mahammad B.
Mamedov, Nazim T.
Abdullayev, Nadir A.
Zverev, Vladimir N.
Alfonsov, Alexey
Kataev, Vladislav
Büchner, Bernd
Schwier, Eike F.
Kumar, Shiv
Kimura, Akio
Petaccia, Luca
Di Santo, Giovanni
Vidal, Raphael C.
Schatz, Sonja
Kißner, Katharina
Ünzelmann, M.
Min, Chul-Hee
Moser, Simon K.
Peixoto, Thiago R. F.
Reinert, Friedrich
Ernst, Arthur
Echenique, Pedro M.
Isaeva, Anna
Chulkov, Evgueni V.
Materials Science
Magnetic topological insulators (MTIs) are narrow gap semiconductor materials that combine non-trivial band topology and magnetic order. Unlike their nonmagnetic counterparts, MTIs may have some of the surfaces gapped due to breaking the time-reversal symmetry, which enables a number of exotic phenomena having potential applications in spintronics. So far, MTIs have only been created by means of doping nonmagnetic TIs with 3d transition metal elements, however, such an approach leads to strongly inhomogeneous magnetic and electronic properties of these materials, restricting the observation of important effects to very low temperatures. Finding intrinsic MTI, i.e. a stoichiometric well-ordered magnetic compound, could be an ideal solution to these problems, but no such material was observed to date. Here, using density functional theory we predict and further confirm by means of structural, transport, magnetic, angle- and spin-resolved photoemission spectroscopy measurements the realization of the antiferromagnetic (AFM) TI phase, that is hosted by the van der Waals layered compound MnBi$_2$Te$_4$. An interlayer AFM ordering makes MnBi$_2$Te$_4$ invariant with respect to the combination of the time-reversal ($Θ$) and primitive-lattice translation ($T_{1/2}$) symmetries, $S = ΘT_{1/2}$, giving rise to the $Z_2$ topological classification of AFM insulators. We find $Z_2 = 1$ for MnBi$_2$Te$_4$, which confirms its topologically nontrivial nature. The $S$-breaking (0001) surface of MnBi$_2$Te$_4$ exhibits a giant bandgap in the topological surface state as evidenced by ab initio calculations and photoemission measurements. These results culminate almost a decade-long search of an AFMTI, predicted in 2010. Furthermore, MnBi$_2$Te$_4$ is the first intrinsic magnetic TI realized experimentally.
title Prediction and observation of the first antiferromagnetic topological insulator
topic Materials Science
url https://arxiv.org/abs/1809.07389