Ordering of magnetic impurities and tunable electronic properties of topological insulators

Abstract

We study collective behavior of magnetic adatoms randomly distributed on the surface of a topological insulator. As a consequence of the spin-momentum locking on the surface, the RKKY-type interactions of two adatom spins depend on the direction of the vector connecting them, thus interactions of an ensemble of adatoms are frustrated. We show that at low temperatures the frustrated RKKY interactions give rise to two phases: an ordered ferromagnetic phase with spins pointing perpendicular to the surface, and a disordered spin-glass-like phase. The two phases are separated by a quantum phase transition driven by the magnetic exchange anisotropy. Ferromagnetic ordering occurs via a finite-temperature phase transition. The ordered phase breaks time-reversal symmetry spontaneously, driving the surface states into a gapped state, which exhibits an anomalous quantum Hall effect and provides a realization of the parity anomaly. We find that the magnetic ordering is suppressed by potential scattering. Our work indicates that controlled deposition of magnetic impurities provides a way to modify the electronic properties of topological insulators.

4+ pages, 2 figures

References in corpus (6)

• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Topological Field Theory of Time-Reversal Invariant Insulators
• Electron transport in disordered graphene
• Long-Range Interaction Between Adatoms in Graphene
• Sublattice ordering in a dilute ensemble of defects in graphene
• Zero-temperature phase of the XY spin glass in two dimensions: Genetic embedded matching heuristic

Cited by in corpus (20)

• Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
• Surface quantized anomalous Hall current and magneto-electric effect in magnetically disordered topological insulators
• Imaging Dirac-Mass Disorder from Magnetic Dopant-Atoms in the Ferromagnetic Topological Insulator Cr${}_x$(Bi${}_{0.1}$Sb${}_{0.9}$)${}_{2-x}$Te${}_3$
• Signatures of Dirac fermion-mediated magnetic order
• Filling of magnetic-impurity-induced gap in topological insulators by potential scattering
• RKKY Interaction On Surfaces of Topological Insulators With Superconducting Proximity Effect
• Weak Localization and Antilocalization in Topological Materials with Impurity Spin-Orbit Interactions
• Gate-Tunable Exchange Coupling Between Cobalt Clusters on Graphene
• Spin Susceptibility and Helical Magnetic Orders at the Edges/Surfaces of Topological Insulators Due to Fermi Surface Nesting
• Quantum Transport in Weyl Semimetal Thin Films in the Presence of Spin-Orbit Coupled Impurities
• Focusing RKKY interaction by graphene P-N junction
• Indirect exchange interaction between magnetic impurities in the two-dimensional topological insulator based on CdTe/HgTe/CdTe quantum wells
• Interlayer RKKY Coupling in Bulk Rashba Semiconductors under Topological Phase Transition
• Ferromagnetism and glassiness on the surface of topological insulators
• Interplay between Mn-acceptor state and Dirac surface states in Mn-doped Bi${}_2$Se${}_3$ topological insulator
• Anisotropic RKKY interactions mediated by $j=3/2$ quasiparticles in half-Heusler topological semimetal
• Topological insulator in a helicoidal magnetization field
• RKKY interaction in graphene at finite temperature
• Thermodynamics of Two-impurity Anderson Model with Dzyaloshinskii-Moriya Interaction
• Bulk Saturable absorption in Topological Insulator thin Films