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Emerging part of condensed matter science, which deals with the systems of extreme two‐dimensionality, renews the interest in natural 2D objects such as planar stacking faults (SFs) in semiconductor crystals. We report on the observation of an excitonic state localized at the 1D intersection of the SF with a high quality ZnSe quantum well (QW). The micro‐photoluminescence measurements are performed in a specimen used for preceding transmission electron microscopy studies. We demonstrate that the observed narrow lines are polarized along SFs and their linewidths depend on the SFs length. For short SFs, the linewidth can be as low as 0.15 meV. Using the combination of the effective mass approach and the density functional theory calculations we show that the exciton localization is due to the intrinsic electric field inside the SF, which also leads to a spatial separation of electron and hole in the exciton. The 1D intersection of perfect natural and artificial 2D objects can serve as a promising playground for the study of subtle excitonic effects in single defects. [ABSTRACT FROM AUTHOR]

• Multi-gate FD-SOI qubit MOS devices were electrically characterized. • At deep cryogenic temperatures and in linear regime, oscillations in both the current and the transconductance were observed above threshold. • These are likely related to the formation of one-dimensional sub-bands in the silicon active region. • A compact model taking into account a 1D density of states (DOS) has been developed in order to fathom how the 1D confinement influences both the inversion charge and the transconductance. • Furthermore, the impact of drain voltage was also investigated, showing that the oscillations were smoothed out at high drain biases. Multi-gate FD-SOI qubit MOS devices were electrically characterized. At deep cryogenic temperatures and in linear regime, oscillations in both the current and the transconductance were observed above threshold. These are likely related to the formation of one-dimensional sub-bands in the silicon active region. A compact model taking into account a 1D density of states (DOS) has been developed in order to fathom how the 1D confinement influences both the inversion charge and the transconductance. The impact of temperature was shown to be crucial in order to distinguish the sub-bands contribution to the transconductance oscillations. Furthermore, the impact of drain voltage was also investigated, showing that the oscillations were smoothed out at high drain biases. [ABSTRACT FROM AUTHOR]

Water confined into the interior channels of narrow carbon nanotubes or transmembrane proteins forms collectively oriented molecular wires held together by tight hydrogen bonds. Here, we explore the thermodynamic stability and dipolar orientation of such 1 D water chains from nanoscopic to macroscopic dimensions. We show that a dipole lattice model accurately recovers key properties of 1D confined water when compared to atomically detailed simulations. In a major reduction in computational complexity, we represent the dipole model in terms of effective Coulombic charges, which allows us to study pores of macroscopic lengths in equilibrium with a water bath (or vapor). We find that at ambient conditions, the water chains filling the tube are essentially continuous up to macroscopic dimensions. At reduced water vapor pressure, we observe a 1D Ising-like filling/emptying transition without a true phase transition in the thermodynamic limit. In the filled state, the chains of water molecules in the tube remain dipole-ordered up to macroscopic lengths of ≈O.1 mm, and the dipolar order is estimated to persist for times up to ≈O.1 s. The observed dipolar order in continuous water chains is a precondition for the use of nanoconfined 1D water as mediator of fast long-range proton transport, e.g., in fuel cells. For water-filled nanotube bundles and membranes, we expect anti-ferroelectric behavior, resulting in a rich phase diagram similar to that of a 2D Coulomb gas. [ABSTRACT FROM AUTHOR]

Locally induced, magnetic order on the surface of a topological insulator nanowire could enable room-temperature topological quantum devices. Here we report on the realization of selective magnetic control over topological surface states on a single facet of a rectangular Bi2Te3 nanowire via a magnetic insulating Fe3O4 substrate. Low-temperature magnetotransport studies provide evidence for local time-reversal symmetry breaking and for enhanced gapping of the interfacial 1D energy spectrum by perpendicular magnetic-field components, leaving the remaining nanowire facets unaffected. Our results open up great opportunities for development of dissipation-less electronics and spintronics.

In graphene, the extremely fast charge carriers can be controlled by electron-optical elements, such as waveguides, in which the transmissivity is tuned by the wavelength. In this work, charge carriers are guided in a suspended ballistic few-mode graphene channel, defined by electrostatic gating. By depleting the channel, a reduction of mode number and steps in the conductance are observed, until the channel is completely emptied. The measurements are supported by tight-binding transport calculations including the full electrostatics of the sample.