Optical evidence of blue shift in topological insulator bismuth selenide in the few-layer limit
arXiv:1703.01019 · doi:10.1063/1.4982631
Abstract
Optical band gap properties of high-quality few-layer topological insulator Bi2Se3 thin films grown with magnetron sputtering are investigated using broadband absorption spectroscopy. We provide direct optical evidence of a rigid blue-shift to up to 0.5 eV in the band gap of Bi2Se3 as it approaches the two-dimensional limit. The onset of this behavior is most significant below six quintuple layers. The blue shift is very robust and is observed in both protected (capped) and exposed (uncapped) thin films. Our results are consistent with observations that finite-size effects have profound impact on the electronic character of topological insulators, particularly when the top and bottom surface states are coupled. Our result provides new insights, and the need for deeper investigations, into the scaling behavior of topological materials before they can have significant impact on electronic applications.
References in corpus (26)
- Topological Insulators
- Topological insulators and superconductors
- Fault-tolerant quantum computation by anyons
- Non-Abelian Anyons and Topological Quantum Computation
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- Topological Insulators in Three Dimensions
- Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Quantized Anomalous Hall Effect in Magnetic Topological Insulators
- First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
- Spin Transfer Torque Generated by the Topological Insulator Bi_2Se_3
- Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
- Topological Surface States Protected From Backscattering by Chiral Spin Texture
- Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
- Electrically detected interferometry of Majorana fermions in a topological insulator
- Massive Dirac fermions and spin physics in an ultrathin film of topological insulator
- The Coexistence of Superconductivity and Topological Order in the Bi2Se3 Thin Films
- Oscillatory crossover from two dimensional to three dimensional topological insulators
- Bulk Fermi surface coexistence with Dirac surface state in BiSe: a comparison of photoemission and Shubnikov-de Haas measurements
- First Principles Studies on 3-Dimentional Strong Topological Insulators: Bi2Te3, Bi2Se3 and Sb2Te3
- Anomalous Finite Size Effects on Surface States in the Topological Insulator BiSe
- Emerging Weak Localization Effects on Topological Insulator-Insulating Ferromagnet (Bi_2Se_3-EuS) Interface
- Magnetically Defined Qubits on 3D Topological Insulators
- Crossover between Weak Antilocalization and Weak Localization of Bulk States in Ultrathin Bi2Se3 Films
- Conductance modulation in topological insulator Bi2Se3 thin films with ionic liquid gating
- Viable route towards large-area two dimensional MoS2 using magnetron sputtering