Rare Earth Doping of Topological Insulators: A Brief Review of Thin Film and Heterostructure Systems. Issue 8 (11th January 2019)

• Record Type: Journal Article
• Authors: Hesjedal, Thorsten
• Other Names: Modreanu Mircea guestEditor.; Cornet Charles guestEditor.; Durand Olivier guestEditor.; Fujiwara Hiroyuki guestEditor.; Jellison Gerald E. guestEditor.; Bell Gavin guestEditor.; Merckling Clement guestEditor.
• Is Part Of: Physica status solidi. Volume 216:Issue 8(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-01-11
• Subjects: antimony telluride -- bismuth telluride -- heterostructure -- MBE -- rare earth doping -- topological insulators; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201800726
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Magnetic topological insulators (MTIs) are a novel materials class in which a topologically nontrivial electronic band structure coexists with long‐range ferromagnetic order. The ferromagnetic ground state can break time‐reversal symmetry, opening a gap in the topological surface states whose size is dependent on the magnitude of the magnetic moment. Doping with rare earth ions is one way to introduce higher magnetic moments into a material, however, in Bi2 Te3 bulk crystals, the solubility limit is only a few percent. Using molecular beam epitaxy for the growth of doped (Sb, Bi)2 (Se, Te)3 TI thin films, high doping concentrations can be achieved while preserving their high crystalline quality. The growth, structural, electronic, and magnetic properties of Dy, Ho, and Gd doped TI thin films will be reviewed. Indeed, high magnetic moments can be introduced into the TIs, which are, however, not ferromagnetically ordered. By making use of interfacial effects, magnetic long‐range order in Dy doped Bi2 Te3, proximity‐coupled to the MTI Cr:Sb2 Te3, has been achieved. Clearly, engineered MTI heterostructures offer new possibilities that combine the advantageous properties of different layers, and thus provide an ideal materials platform enabling the observation new quantum effects at higher temperatures. Abstract : Magnetic topological insulators (MTIs) are a novel materials class in which a topologically nontrivial electronic band structure coexists with long‐range ferromagnetic order, unlocking exotic physical phenomena. Here, the molecular beam epitaxy growth, structural, electronic, and magnetic properties of Dy, Ho, and Gd doped MTI thin films are reviewed. Engineered MTI heterostructures offer new possibilities that combine the advantageous properties of different layers.