Erhu Zhang

Quantum transport in a curved one-dimensional quantum wire with spin-orbit interactions

The one-dimensional effective Hamiltonian for a planar curvilinear quantum wire with arbitrary shape is proposed in the presence of the Rashba spin-orbit interaction. Single electron propagation through a device of two straight lines conjugated with an arc has been investigated and the analytic expressions of the reflection and transmission probabilities have been derived. The effects of the device geometry and the spin-orbit coupling strength

Buckling and competition of energy and entropy lead conformation of single-walled carbon nanocones

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Half-metallic ferromagnetism in transition-metal doped germanium nitride: A first-principles study

on the reflection and transmission probabilities and the conductance are investigated in the case of spin polarized electron incidence. We find that no spin-flip exists in the reflection of the first junction. The reflection probabilities are mainly influenced by the arc angle and the radius, while the transmission probabilities are affected by both spin-orbit coupling and the device geometry. The probabilities and the conductance take the general behavior of oscillation versus the device geometry parameters and

Odd-parity currents induced by dynamic deformations in graphene-like systems

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Strain-tunable electronic and optical properties of BC3 monolayer

. Especially the electron transportation varies periodically versus the arc angle

THE TRANSPORT PROPERTIES OF NANOTUBES AND ITS CURVATURE EFFECTS

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Structure–property relationships of cell clusters in biotissues: 2D analysis

. We also investigate the relationship between the conductance and the electron energy, and find that electron resonant transmission occurs for certain energy. Finally, the electron transmission for the incoming electron with arbitrary state is considered. For the outgoing electron, the polarization ratio is obtained and the effects of the incoming electron state are discussed. We find that the outgoing electron state can be spin polarization and reveal the polarized conditions.

Spin–curvature interaction from curved Dirac equation: Application to single-wall carbon nanotubes

Using a continuum model, expressions for the elastic energy, defect energy, structure entropy, and mixing entropy of carbon nanocones are proposed analytically. The optimal conformation of carbon nanocones is studied by imposing minimization of free energy and analyzing the effects that the buckling of a nanocone’s walls have during formation. The model explains the experimentally observed preference of 19.2° for the cone angle of carbon nanocone. Furthermore, it predicts the optimal conformation of carbon nanocones to result in a cone angle of 19.2°, radius of 0.35nm, and critical length of 24nm, all of which agree very well with experimental observations.

The Aharonov–Bohm effect in the carbon nanotube ring

Abstract We report a first-principles density functional theory study on the electronic and magnetic properties of transition-metal-doped β -Ge 3 N 4 . Transition-metal atoms are found to strongly prefer to occupy substitutional sites and attract each other. The V- and Cr-doped Ge 3 N 4 are ferromagnetic semiconductors; whereas, the Mn- and Fe-doped compounds are ferromagnetic half metals.

Magnetosubbands of semiconductor quantum wires with Rashba and Dresselhaus spin-orbit coupling

Reduced (3  +  1)-dimensional Dirac systems with inter-pseudo-spin and inter-valley scattering are employed to investigate current responses to (chiral) gauge fields in graphene-like systems. From (chiral) current-(chiral) current correlation functions, we derive the current responses. Except for electric currents induced by external gauge fields, we find the inter-valley scattering can break the topological nature of odd-parity currents. Given the proper conditions, this property can help us realize valley-polarized electric currents. Through the dynamic deformations generating the chiral gauge fields, we find the vortex-like currents while their profiles can be tuned by superposition of some deformations. In particular, we find a more manageable approach to realize the topological electric current by choosing a linear dynamic deformation.