Spin transverse force and quantum transverse transport

We present a brief review on spin transverse force, which exerts on the spin as the electron is moving in an electric field. This force, analogue to the Lorentz force on electron charge, is perpendicular to the electric field and spin current carried by the electron. The force stems from the spin-orbit coupling of electrons as a relativistic quantum effect, and could be used to understand the Zitterbewegung of electron wave packet and the quantum transverse transport of electron in a heuristic way.Comment: 4 pages, manuscript of invited talk on IAS Workshop on Spintronics at Nanyang Techological University, Singapore, 200

Fundamental characteristics of transverse deflecting field

The Panofsky-Wenzel theorem connects the transverse deflecting force in an rf structure with the existence of a longitudinal electric field component. In this paper it is shown that a transverse deflecting force is always accompanied by an additional longitudinal magnetic field component which leads to an emittance growth in the direction perpendicular to the transverse force. Transverse deflecting waves can thus not be described by pure TM or TE modes, but require a linear combination of basis modes for their representation. The mode description is preferably performed in the HM--HE basis to avoid converge problems, which are fundamental for the TM--TE basis.Comment: The sign in Eq.8 is corrected in May 201

Nonequilibrium structures and dynamic transitions in driven vortex lattices with disorder

We review our studies of elastic lattices driven by an external force $F$ in the presence of random disorder, which correspond to the case of vortices in superconducting thin films driven by external currents. Above a critical force $F_c$ we find two dynamical phase transitions at $F_p$ and $F_t$, with $F_c<F_p<F_t$. At $F_p$ there is a transition from plastic flow to smectic flow where the noise is isotropic and there is a peak in the differential resistance. At $F_t$ there is a sharp transition to a frozen transverse solid where both the transverse noise and the diffussion fall down abruptly and therefore the vortex motion is localized in the transverse direction. From a generalized fluctuation-dissipation relation we calculate an effective transverse temperature in the fluid moving phases. We find that the effective temperature decreases with increasing driving force and becomes equal to the equilibrium melting temperature when the dynamic transverse freezing occurs.Comment: 8 pages, 3 fig

Core-Offset Small-Core-Diameter Dispersion Compensation Fiber Interferometer and its Applications in Fiber Sensors

We propose a core-offset small core diameter dispersion compensation fiber (DCF) interferometer and investigate its applications in fiber sensors. If the transverse force is applied to a short section of the DCF, there is almost no crosstalk on the transmission spectrum between the extinction ratio variation induced by the transverse force and the wavelength shift caused by the longitudinal strain or ambient temperature, which can be applied to measure both transverse and longitudinal strain, or both transverse strain and temperature, simultaneously. The proposed sensors have the advantages of low cost, simple and compact structure, and good reproducibility

Transverse force generated by an electric field and transverse charge imbalance in spin-orbit coupled systems

We use linear response theory to study the transverse force generated by an external electric field and hence possible charge Hall effect in spin-orbit coupled systems. In addition to the Lorentz force that is parallel to the electric field, we find that the transverse force perpendicular to the applied electric field may not vanish in a system with an anisotropic energy dispersion. Surprisingly, in contrast to the previous results, the transverse force generated by the electric field does not depend on the spin current, but in general, it is related to the second derivative of energy dispersion only. Furthermore, we find that the transverse force does not vanish in the Rashba-Dresselhaus system. Therefore, the non-vanishing transverse force acts as a driving force and results in charge imbalance at the edges of the sample. The estimated ratio of the Hall voltage to the longitudinal voltage is $\sim 10^{-3}$. The disorder effect is also considered in the study of the Rashba-Dresselhaus system. We find that the transverse force vanishes in the presence of impurities in this system because the vertex correction and the anomalous velocity of the electron accidently cancel each other

Moving glass theory of driven lattices with disorder

We study periodic structures, such as vortex lattices, moving in a random potential. As predicted in [T. Giamarchi, P. Le Doussal Phys. Rev. Lett. 76 3408 (1996)] the periodicity in the direction transverse to motion leads to a new class of driven systems: the Moving Glasses. We analyse using several RG techniques the properties at T=0 and $T>0$: (i) decay of translational long range order (ii) particles flow along static channels (iii) the channel pattern is highly correlated (iv) barriers to transverse motion. We demonstrate the existence of the ``transverse critical force'' at T=0. A ``static random force'' is shown to be generated by motion. Displacements grow logarithmically in $d=3$ and algebraically in $d=2$. The persistence of quasi long range translational order in $d=3$ at weak disorder, or large velocity leads to predict a topologically ordered ``Moving Bragg Glass''. This state continues the static Bragg glass and is stable at $T>0$, with non linear transverse response and linear asymptotic behavior. In $d=2$, or in $d=3$ at intermediate disorder, another moving glass exist (the Moving Transverse Glass) with smectic quasi order in the transverse direction. A phase diagram in $T$ force and disorder for static and moving structures is proposed. For correlated disorder we predict a ``moving Bose glass'' state with anisotropic transverse Meissner effect and transverse pinning. We discuss experimental consequences such as anomalous Hall effect in Wigner crystal and transverse critical current in vortex lattice.Comment: 74 pages, 27 figures, RevTe

A constrained random-force model for weakly bending semiflexible polymers

The random-force (Larkin) model of a directed elastic string subject to quenched random forces in the transverse directions has been a paradigm in the statistical physics of disordered systems. In this brief note, we investigate a modified version of the above model where the total transverse force along the polymer contour and the related total torque, in each realization of disorder, vanish. We discuss the merits of adding these constraints and show that they leave the qualitative behavior in the strong stretching regime unchanged, but they reduce the effects of the random force by significant numerical prefactors. We also show that a transverse random force effectively makes the filament softer to compression by inducing undulations. We calculate the related linear compression coefficient in both the usual and the constrained random force model.Comment: 4 pages, 1 figure, accepted for publication in PR