Persistent ferromagnetism and topological phase transition at the interface of a superconductor and a topological insulator

Abstract

At the interface of an s-wave superconductor and a three-dimensional topological insulator, Ma- jorana zero modes and Majorana helical states have been proposed to exist respectively around magnetic vortices and geometrical edges. Here we first show that a single magnetic impurity at such an interface splits each resonance state of a given spin channel outside the superconducting gap, and also induces two new symmetric impurity states inside the gap. Next we find that an increase in the superconducting gap suppresses both the oscillation magnitude and period of the RKKY inter- action between two interface magnetic impurities mediated by BCS quasi-particles. Within a mean field approximation, the ferromagnetic Curie temperature is found to be essentially independent of the superconducting gap, an intriguing phenomenon due to a compensation effect between the short-range ferromagnetic and long-range anti-ferromagnetic interactions. The existence of persis- tent ferromagnetism at the interface allows realization of a novel topological phase transition from a non-chiral to a chiral superconducting state at sufficiently low temperatures, providing a new platform for topological quantum computation.

arXiv comment5 pages, 3 figures

References in corpus (21)

• Topological insulators and superconductors
• Fault-tolerant quantum computation by anyons
• Non-Abelian Anyons and Topological Quantum Computation
• Berry Phase Effects on Electronic Properties
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• A generic new platform for topological quantum computation using semiconductor heterostructures
• Non-abelian statistics of half-quantum vortices in p-wave superconductors
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Majorana fermions in a tunable semiconductor device
• Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
• Magnetic impurities on the surface of a topological insulator
• The Coexistence of Superconductivity and Topological Order in the Bi2Se3 Thin Films
• Chiral Topological Superconductor From the Quantum Hall State
• Quasiparticle States near the Surface and the Domain Wall in a p_x\pm i p_y-Wave Superconductor
• Electrically controllable surface magnetism on the surface of topological insulator
• Fully gapped topological surface states in Bi${}_2$Se${}_3$ films induced by a d-wave high-temperature superconductor
• RKKY Interaction On Surfaces of Topological Insulators With Superconducting Proximity Effect
• Optimization of Mn Doping in Group-IV-based Dilute Magnetic Semiconductors by Electronic Co-dopants

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• Tuning topological surface magnetism by bulk alloying