2019/08/05 by Masomeh Arabikhah, Alireza Saffarzadeh
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Geometry #Graphene research and applications #Magnetic field #Magnetoresistance #Physics #Quantum mechanics #Quantum tunnelling #Surface (topology) #Surface states #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/1361-648x/ab31f4
published as J. Phys.: Condens. Matter 31, 445001 (2019) · 8 pages, 8 figures
openalex publication_date 2019/08/05 · arxiv created 2019/08/11 · arxiv updated 2019/08/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We explore the scattering of Dirac electrons in a double-gated topological insulator in the presence of magnetic proximity effects and warped surface states. It is found that a magnetic field can shift the Dirac cone in momentum space and deform the constant-energy contour, or opens up a band gap at the Dirac point, depending on the magnetization orientation. The double gate voltage induces quantum wells and/or quantum barriers on the surface of topological insulators, generating surface resonant tunnelling states. It is found that the hexagonal warping effect can increase the electronic transport at high energies when the constant-energy contour exhibits a snowflake shape. The energy-dependent conductances in the parallel and antiparallel magnetic configurations exhibit out-of-phase oscillations due to the quantum interference of propagating waves in the region between the two magnetized segments. Although the conductance spectrum of the double-well structure is higher than that of the double-barrier structure, the magnetoresistance ratio versus the separation distance between the two magnetized barriers exhibits pronounced oscillations due to the resonant tunnelling states. We show that the surface state transport can be controlled by the exchange field and gate voltage without breaking time reversal symmetry, suggesting that the double gated and magnetized topological insulators can be utilized to achieve a large magnetoresistance ratio with a tunable sign.