We study how the electronic structure of a single bilayer Bi on a single quintuple layer Bi2Se3 (Bi2Te3) changes with interface polarization, strain and H adsorption using first-principles calculations. We find that for strained systems the Dirac cone state does not show in the band gap. Coupled with strain and H adsorption, the six spin-polarized Dirac cones in the band gap are created by the interfacing two gapped films. The internal electrical field can result in variations in the work function relative to Bi and Bi2Se3 surfaces. Our findings confirm that the interface polarization, strain and atomic adsorption are the effective means to manipulate electronic structures and topological states on non-metallic surfaces, which could be helpful for realizing atomically thin spintronic devices.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c5cp02618k | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Local probe of bulk and edge states in a fractional Chern insulator.
Nature
November 2024
Department of Physics, Stanford University, Stanford, CA, USA.
The fractional quantum Hall effect is a key example of topological quantum many-body phenomena, arising from the interplay between strong electron correlation, topological order and time-reversal symmetry breaking. Recently, a lattice analogue of the fractional quantum Hall effect at zero magnetic field has been observed, confirming the existence of a zero-field fractional Chern insulator (FCI). Despite this, the bulk-edge correspondence-a hallmark of a FCI featuring an insulating bulk with conductive edges-has not been directly observed.
View Article and Find Full Text PDFDirac-Like Fermions Anomalous Magneto-Transport in a Spin-Polarized Oxide 2D Electron System.
Adv Mater
January 2025
CNR-SPIN, Complesso Univ. Monte S. Angelo, Naples, I-80126, Italy.
In a 2D electron system (2DES) the breaking of the inversion, time-reversal and bulk crystal-field symmetries is interlaced with the effects of spin-orbit coupling (SOC) triggering exotic quantum phenomena. Here, epitaxial engineering is used to design and realize a 2DES characterized simultaneously by ferromagnetic order, large Rashba SOC and hexagonal band warping at the (111) interfaces between LaAlO, EuTiO, and SrTiO insulators. The 2DES displays anomalous quantum corrections to the magneto-conductance driven by the time-reversal-symmetry breaking occurring below the magnetic transition temperature.
View Article and Find Full Text PDFEdge Zeros and Boundary Spinons in Topological Mott Insulators.
Phys Rev Lett
September 2024
Institut für Theoretische Physik und Astrophysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, 97074 Würzburg, Germany.
We use a real-space slave-rotor theory of the physics of topological Mott insulators, using the Kane-Mele-Hubbard model as an example, and show that a topological gap in the Green function zeros corresponds to a gap in the bulk spinon spectrum and implies a gapless band of edge zeros and a spinon edge mode. We then consider an interface between a topological Mott insulator and a conventional topological insulator showing how the spinon edge mode of the topological Mott insulator combines with the spin part of the conventional electron topological edge state, leaving a non-Fermi liquid edge mode described by a gapless propagating holon and gapped spinon state. Our work demonstrates the physical meaning of Green function zeros and shows that interfaces between conventional and Mott topological insulators are a rich source of new physics.
View Article and Find Full Text PDFSpin-Dependent ππ^{*} Gap in Graphene on a Magnetic Substrate.
Phys Rev Lett
June 2024
CNR-Istituto di Struttura della Materia (CNR-ISM), Via del Fosso del Cavaliere 100, 00133 Roma, Italy.
We present a detailed analysis of the electronic properties of graphene/Eu/Ni(111). By using angle- and spin-resolved photoemission spectroscopy and ab initio calculations, we show that the intercalation of Eu in the graphene/Ni(111) interface gives rise to a gapped freestanding dispersion of the ππ^{*} Dirac cones at the K[over ¯] point with an additional lifting of the spin degeneracy due to the mixing of graphene and Eu states. The interaction with the magnetic substrate results in a large spin-dependent gap in the Dirac cones with a topological nature characterized by a large Berry curvature and a spin-polarized Van Hove singularity, whose closeness to the Fermi level gives rise to a polaronic band.
View Article and Find Full Text PDFBoltzmann Switching MoS Metal-Semiconductor Field-Effect Transistors Enabled by Monolithic-Oxide-Gapped Metal Gates at the Schottky-Mott Limit.
Adv Mater
July 2024
Department of Electrical and Computer Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
Article Synopsis
- A new device architecture called van der Waals Schottky gated metal-semiconductor FETs (vdW-SG MESFETs) uses molybdenum disulfide (MoS) channels with surface-oxidized metal gates to improve performance in field-effect transistors (FETs).
- These MESFETs operate at low gate voltages under 0.5 volts and demonstrate ideal switching behavior due to the strong coupling at the Schottky junction, achieving minimal energy loss during operation.
- The study shows that improving the interface between the metal gate and the MoS channel can enhance performance by eliminating unwanted states, leading to a new approach for developing efficient 2D electronic devices.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!