Discovery of a high-temperature antiferromagnetic state and transport signatures of exchange interactions in a Bi2Se3/EuSe heterostructure

Abstract

Spatial confinement of electronic topological surface states (TSS) in topological insulators poses a formidable challenge because TSS are protected by time-reversal symmetry. In previous works formation of a gap in the electronic spectrum of TSS has been successfully demonstrated in topological insulator/magnetic material heterostructures, where ferromagnetic exchange interactions locally lifts the time-reversal symmetry. Here we report an experimental evidence of exchange interaction between a topological insulator Bi2Se3 and a magnetic insulator EuSe. Spin-polarized neutron reflectometry reveals a reduction of the in-plane magnetic susceptibility within a 2 nm interfacial layer of EuSe, and the combination of SQUID magnetometry and Hall measurements points to the formation of an antiferromagnetic layer with at least five-fold enhancement of Néel's temperature. Abrupt resistance changes in high magnetic fields indicate interfacial exchange coupling that affects transport in a TSS. High temperature local control of TSS with zero net magnetization unlocks new opportunities for the design of electronic, spintronic and quantum computation devices, ranging from quantization of Hall conductance in zero fields to spatial localization of non-Abelian excitations in superconducting topological qubits.

References in corpus (8)

• Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures
• Proximity effect between a topological insulator and a magnetic insulator with large perpendicular anisotropy
• Absence of magnetic-proximity effect at the interface of Bi${}_2$Se${}_3$ and (Bi,Sb)${}_2$Te${}_3$ with EuS
• Dirac-Electrons-Mediated Magnetic Proximity Effect in Topological Insulator / Magnetic Insulator Heterostructures
• Do topology and ferromagnetism cooperate at the EuS/Bi${}_2$Se${}_3$ interface?
• Partial Charge Transfer and Absence of Induced Magnetization in EuS(111)/Bi${}_2$Se${}_3$ Heterostructures
• Search for enhanced magnetism at the interface between Bi${}_2$Se${}_3$ and EuSe
• Epitaxial growth and magnetic characterization of EuSe thin films with various crystalline orientations

Cited by in corpus (2)

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