September 17, 2002
Similar papers 3
May 19, 1995
We examine the dynamical consequences of Berry's phase for Josephson junctions, junction arrays, and their vortices. Josephson's equation and the related phase slip voltages are shown to be uneffected by Berry's phase. In an annular Josephson junction, Berry's phase is seen to generate a new current drive on a vortex. In the continuum limit, vortex dynamics in a 2D array is shown to map onto that of a 2D film. A Hall sign anomaly is expected in arrays; and the merits of array...
February 16, 1996
Based on a recent work (Thouless, Ao, and Niu, Transverse force on a quantized vortex in a superfluid) I show that the spectral or momentum flow due to a moving vortex is identical to the phase slippage process discussed by Josephson and Anderson. I also show that the force due to the spectral flow is the reaction force of the Magnus force, and that the two forces act on different objects. Therefore one can conclude that the evaluation of the spepctral flow confirms the resul...
September 29, 1997
We investigate the problem of forces on moving vortex in a superfluid or superconductor. The main purpose is to locate the source which leads to the contradictory results in the literature. We establish the connection between this problem to the difficult but well studied subject of resistivity formula in transport theory. The relaxation time approximation used in the force calculation via force-force correlation function is shown to be invalid. The roles of Berry's pha...
June 7, 2004
We study a system of large number of singly quantized vortices in a BEC confined in a rotating toroidal geometry. Analogous to the Meissner effect in supercomputers, we show that the external rotational field can be tuned to can cancel the Magnus field, resulting in a zero vortex flux. We also show that the Berry's phase for this system is directly related to the vortex flux.
June 2, 2021
At sufficiently low temperatures magnetic materials often enter a correlated phase hosting collective, coherent magnetic excitations such as magnons or triplons. Drawing on the enormous progress on topological materials of the last few years, recent research has led to new insights into the geometry and topology of these magnetic excitations. Berry phases associated to magnetic dynamics can lead to observable consequences in heat and spin transport while analogues of topologi...
March 30, 1996
We discuss the nondissipative Magnus-type force acting on linear defects in Fermi systems, such as Abrikosov vortices in superconductors, singular and continuous vortices in superfluid phases of $^3$He, magnetic vortices and skyrmions in ferromagnets. Spectral flow of fermion zero modes in the vortex core gives an essential contribution to the nondissipative force, which is confirmed in Manchester experiments on rotating $^3$He-B. The spectral flow effect is closely related t...
July 7, 1995
We present a microscopic derivation of the equation of motion for a vortex in a superconductor. A coherent view on vortex dynamics is obtained, in which {\it both} hydrodynamics {\it and} the vortex core contribute to the forces acting on a vortex. The competition between these two provides an interpretation of the observed sign change in the Hall angle in superconductors with mean free path $l$ of the order of the coherence length $\xi$ in terms of broken particle-hole symme...
August 2, 2023
The velocity field composed of the Berry connection from many-body wave functions and electromagnetic vector potential explains the energy-momentum balance during the reversible superconducting-normal phase transition in the presence of an externally applied magnetic field. In this formalism, forces acting on electrons are the Lorentz force and force expressed as the gradient of the kinetic energy. In the stationary situation, they balance; however, an infinitesimal imbalance...
May 23, 2019
We propose a scheme for the use of magnetic force microscopy to manipulate Majorana zero modes emergent in vortex cores of topological superconductors in the Fe(Se,Te) family. We calculate the pinning forces necessary to drag two vortices together and the resulting change in current and charge density of the composite fermion. A possible algorithm for measuring and altering Majorana pair parity is demonstrated.
August 30, 2002
In magnetic systems, electronic bands often acquire nontrivial topological structure characterized by gauge flux distribution in momentum (k)-space. It sometimes follows that the phase of the wavefunctions cannot be defined uniquely over the whole Brillouin zone. In this Letter we develop a theory of superconductivity in the presence of this gauge flux both in two- and three-dimensional systems. It is found that the superconducting gap has "nodes" as a function of k where the...