Electronic properties of Bi₂Se₃ dopped by 3d transition metal (Mn, Fe, Co, or Ni) ions

Abstract

Topological insulators are characterized by the existence of band inversion and the possibility of the realization of surface states. Doping with a magnetic atom, which is a source of the time-reversal symmetry breaking, can lead to realization of novel magneto-electronic properties of the system. In this paper, we study effects of substitution by the transition metal ions (Mn, Fe, Co and Ni) into Bi2Se3 on its electric properties. Using the ab inito supercell technique, we investigate the density of states and the projected band structure. Under such substitution the shift of the Fermi level is observed. We find the existence of nearly dispersionless bands around the Fermi level associated with substituted atoms, especially, in the case of the Co and Ni. Additionally, we discuss the modification of the electron localization function as well as charge and spin redistribution in the system. Our study shows a strong influence of the transition metal-Se bond on local modifications of the physical properties. The results are also discussed in the context of the interplay between energy levels of the magnetic impurities and topological surface states.

Influence of Doping on the Topological Surface States of Crystalline Bi2Se3 Topological Insulators

“…Changing the TSS may only appear as a consequence of changing the structure of the bulk bands, which is visible from Figure 6 (in particular for the Fe-doped sample). Thus, our experiment clearly confirms the results of the DFT calculations of the bulk electronic structure of the Fe-doped Be 2 Se 3 published recently [ 26 , 27 ].…”

“…To address these questions, a rarely seen in literature combined observations of local topography (STM), electronic structure (STS, ARPES) and magnetoresistance (which allows observing SdH quantum oscillations) were conducted. The results are discussed in comparison to the modified electronic structure as obtained in the recent theoretical calculations [ 26 , 27 ].…”

Dynamical Study of the Origin of the Charge Density Wave in $A$V$_{3}$Sb$_{5}$ ($A=$K, Rb, Cs) Compounds

“…However, as we show earlier, the distorted kagome-like plane disturbs the positions of the Sb atoms of neighboring layers, so consequently, the influence of 3D (bulk) CDW is also noticeable in this surface. Similar effect was observed by studying the surface states of Bi 2 Se 3 where the surface charges were modified by the vacancies or atom substitution in the interior of bulk material [105][106][107], due to realization of long-range orbital hybridization [108]. Concluding, the observed stripe-like superstructure is related to a subtle effects of the surface reconstruction and the atomic orbitals hybridization rather than an exact 3D CDW emerging in the AV 3 Sb 5 .…”

Termination dependence of the surface states in Pb$_{2}$Pd

“…Best example of such states are the "metallic" surface states observed experimentally within the angle-resolved photoemission spectroscopy (ARPES) in the topological insulators [3][4][5]. The topological surface states preserve theirs properties also in presence of the magnetic impurities [6][7][8], and that in the presence of intrinsic magnetism can be source of new classes of magnetic topological insulators [9][10][11][12]. More recently, realization of the Dirac [13][14][15], Weyl [16][17][18][19][20], or nodal line [21][22][23][24][25][26][27] semimetals have drawn a lot of attention too.…”