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Pei Wang

Publications and source records attributed to Pei Wang.

315 records · Page 18Linked to original sources
arXiv2007

Nonvanishing spin Hall currents in the presence of magnetic impurities

The intrinsic spin Hall conductivity in a two dimensional electron gas with Rashba spin-orbit coupling is evaluated by taking account of anisotropic coupling between magnetic impurities and itinerant electrons. In our calculation Kubo's linear response formalism is employed and the vertex correction is considered. In the semiclassical limit $μ\gg 1/τ$, a non-vanishing spin Hall conductivity $σ^{}_{sH}$ is found to depend on the momentum relaxation time $τ$, spin-orbit splitting $Δ$ and the anisotropic coefficient of interaction between itinerant electrons and magnetic impurities. The clean limit of $σ^{}_{sH}$ is in the region of $e/8π\sim e/6π$, depending on the anisotropic coefficient.

cond-mat.mes-hall↗
arXiv2006

Spin precession caused by spin-spin interaction between bounded electrons in quantum dots

In this paper, we study the spin-spin interaction between two electrons bounded in a quantum dot. The result shows that spin-spin interaction will cause a pair of spins precessing synchronously. If the two spins are parallel at initial time, the total spin oscillates as a cosine function. If the two spins are antiparallel at initial time, the total spin keeps zero. The precessing period is proportional to the cube of quantum dot radius. For a 2D round quantum dot with radius $R=50{\text{nm}}$, the precessing period equals nearly $12μ{\text{s}}$.

cond-mat.mes-hall↗
arXiv2005

Correlations of spin-polarized and entangled electrons with Berry phase

The correlation and fluctuation of both entangled electrons and spin-polarized pairs affected by two rotating magnetic fields in a setup proposed by J. Carlos Egues etc. (Phys. Rev. Lett. {\bf 89}(2002) 176401) are studied theoretically by using scattering approach. Differing from polarized pair, the entangled electron pairs are shown to behave like a composite particle with the total spins and its $z$ components. The singlet and triplet states exhibit different bunching and antibunching features, which can be easily adjusted by the magnetic fields. The correlations and variances can show up distinguish output signals for the four incident states. Our results are expected to be tested by using coincident technique.

cond-mat.mes-hall↗
arXiv2000

W-symmetries on the Homogeneous Space G/U(1)^r

A construction of $W$-symmetries is given only in terms of the nonlocal fields (parafermions ${\ps}_{\al}$), which take values on the homogeneous space $G/U(1)^r$, where $G$ is a simply connected compact Lie group manifold (its accompanying Lie algebra ${\cal G}$ is a simple one of rank $r$). Only certain restriction of the root set of Lie algebra on which the parafermionic fields take values are satisfied, then a consistent and non-trivial extension of the stress momentum tensor may exist. For arbitrary simple-laced algebras, i.e. the $A-D-E$ cases, a more detailed discussion is given. The OPE of spin three primary field are calculated, in which a primary field with spin four is emerging.

hep-th↗
arXiv1999

Rotation of D-brane and Non-commutative Geometry

Our motivation is to find the relationship between the commutator of coordinates and uncertainty relation involving only the coordinates. The boundary condition with constant background field is connected with the rotation of D-brane at general angle. And the mode expansions of D-brane we found is more reasonable than those appeared in literature. The partition functions and scattering amplitudes are also discussed.

hep-th↗
arXiv1997

Nonelectromagnetic duality in twisted N=4 model

In this paper we discuss the possible existing correlation functions in the N=4 topological model. Due to the distinguished feature that no anomaly exists in N=4 supersymmetric theories, the positive-negative ghost number balance has to be taken into account while considering the correlation functions. On restriction to Kahler manifolds we may find a perturbative mass term which breaks the N=4 supersymmetry down to N=1. In all of these, a nonelectromagnetic duality plays an important role. Moreover, to get a computable generating functional the existence of a proper vanishing theorem is required.

hep-th↗
arXiv1995

A Suggestion for Modification of Vafa-Witten Theory

Using the Mathai-Quillen formalism we reexamine the twisted N=4 supersymmetric model of Vafa-Witten theory. Smooth out the relation between the supersymmetric action and the path integral representation of the Thom class.

hep-th↗