Proximity-induced superconductivity in epitaxial topological insulator/graphene/gallium heterostructures.

The introduction of superconductivity to the Dirac surface states of a topological insulator leads to a topological superconductor, which may support topological quantum computing through Majorana zero modes. The development of a scalable material platform is key to the realization of topological quantum computing. Here we report on the growth and properties of high-quality (Bi,Sb)Te/graphene/gallium heterostructures.

Tunable 2D Group-III Metal Alloys.

Chemically stable quantum-confined 2D metals are of interest in next-generation nanoscale quantum devices. Bottom-up design and synthesis of such metals could enable the creation of materials with tailored, on-demand, electronic and optical properties for applications that utilize tunable plasmonic coupling, optical nonlinearity, epsilon-near-zero behavior, or wavelength-specific light trapping. In this work, it is demonstrated that the electronic, superconducting, and optical properties of air-stable 2D metals can be controllably tuned by the formation of alloys.

Rules for Phase Shifts of Quantum Oscillations in Topological Nodal-Line Semimetals.

Nodal-line semimetals are topological semimetals in which band touchings form nodal lines or rings. Around a loop that encloses a nodal line, an electron can accumulate a nontrivial π Berry phase, so the phase shift in the Shubnikov-de Haas (SdH) oscillation may give a transport signature for the nodal-line semimetals. However, different experiments have reported contradictory phase shifts, in particular, in the WHM nodal-line semimetals (W=Zr/Hf, H=Si/Ge, M=S/Se/Te).

Impact and Origin of Interface States in MOS Capacitor with Monolayer MoS and HfO High-k Dielectric.

Two-dimensional layered semiconductors such as molybdenum disulfide (MoS) at the quantum limit are promising material for nanoelectronics and optoelectronics applications. Understanding the interface properties between the atomically thin MoS channel and gate dielectric is fundamentally important for enhancing the carrier transport properties. Here, we investigate the frequency dispersion mechanism in a metal-oxide-semiconductor capacitor (MOSCAP) with a monolayer MoS and an ultra-thin HfO high-k gate dielectric.

Surface reactivity enhancement by O dissociation on a single-layer MgO film deposited on metal substrate.

Improving reactivity on an insulating surface is crucial due to its important applications in surface catalytic reactions. In this work, we carried out first-principles calculations to investigate the adsorption of O on a single-layer MgO(100) film deposited on a metal substrate. The adsorption configurations, reaction pathways, molecular dynamics simulations, and electronic properties are reported.