Superinjection from Oriented Carbyne as the Result of Landau Quantization in Giant Pseudo-Magnetic Field

The qualitative explanation of the earlier published experimental data was obtained within new energetic model of oriented carbyne. The conductivity spectrum and the superinjection effect feature Landau quantization in a giant pseudomagnetic field. The relativistic dispersion of carriers and non-dissipative character of their motion cause the effect of superinjection where carriers go upwards on an energetic ladder. Raman-spectra and other data point out to the fact that the plane of carriers’ motion is close to the carbyne-insulator interface. Quantum effects and on-surface conductivity allow considering oriented carbyne as an analogue of topological insulator.

Nanoscale strain engineering of graphene and graphene-based devices

Structural distortions in nano-materials can induce dramatic changes in their electronic properties. This situation is well manifested in graphene, a two-dimensional honeycomb structure of carbon atoms with only one atomic layer thickness. In particular, strained graphene can result in both charging effects and pseudo-magnetic fields, so that controlled strain on a perfect graphene lattice can be tailored to yield desirable electronic properties. Here, we describe the theoretical foundation for strain-engineering of the electronic properties of graphene, and then provide experimental evidence for strain-induced pseudo-magnetic fields and charging effects in monolayer graphene. We further demonstrate the feasibility of nano-scale strain engineering for graphene-based devices by means of theoretical simulations and nano-fabrication technology.

Transport property of inhomogeneous strained graphene

In analogy to real magnetic field, the pseudo-magnetic field (PMF) induced by inhomogeneous strain can also formthe Landau levels and edge states. In this paper, the transport properties of graphene under inhomogeneous strain arestudied. We find that the Landau levels have non-zero group velocity, and construct one-dimensional conducting channels.In addition, the edge states and the Landau level states in PMF are both fragile under disorder. We also confirm that thebackscattering of these states could be suppressed by applying a real magnetic filed (MF). Therefore, the transmissioncoefficient for each conducting channel can be manipulated by adjusting the MF strength, which indicates the applicationof switching devices.

A Simplified Approach to the Problems of Room-Temperature Superconductivity

An attempt to simplify the approach to the problems of room-temperature superconductors was done. The key factor has been highlighted—a giant spin-orbit interaction as a result of specific geometry of crystal. Considering oriented carbyne as an example, it was shown that maximal value of SOC was attained in low-dimensional systems. A qualitative model of superconductivity in the localized phase with “pseudo-magnetic field” and “Rashba effective field” as parameters was presented. Their correlation was shown via geometry of electric microfields of crystal. Oriented carbyne was presented as localized phase of room-temperature superconductor and the recipe of its transformation to macroscopic superconductivity was given.

声学三维量子霍尔态的观测

Quantum Hall effect,the quantized transport phenomenon of electrons under strong magnetic fields,remains one of the hottest research topics in condensed matter physics since its discovery in 2D electronic systems.Recently,as a great advance in the research of quantum Hall effects,the quantum Hall effect in 3D systems,despite its big challenge,has been achieved in the bulk ZrTe_(5)and Cd_(3)As_(2)materials.Interestingly,Cd_(3)As_(2)is a Weyl semimetal,and quantum Hall effect is hosted by the Fermi arc states on opposite surfaces via the Weyl nodes of the bulk,and induced by the unique edge states on the boundaries of the opposite surfaces.However,such intriguing edge state distribution has not yet been experimentally observed.Here,we aim to reveal experimentally the unusual edge states of Fermi arcs in acoustic Weyl system with the aid of pseudo-magnetic field.Benefiting from the macroscopic nature of acoustic crystals,the pseudo-magnetic field is introduced by elaborately designed the gradient onsite energy,and the edge states of Fermi arcs on the boundaries of the opposite surfaces are unambiguously demonstrated in experiments.Our system serves as an ideal and highly tunable platform to explore the Hall physics in 3D system,and has the potential in the application of new acoustic devices.