Superconducting vortices in layered materials

In highly anisotropic superconductors such as BSCCO, the vortex lattice is composed of individual pancake vortices. These pancakes, which interact both magnetically and through Josephson coupling, align under certain conditions into elastic lines resembling those found in isotropic superconductors. Three-dimensional (3D) line-like behavior has been observed in transformer geometry measurements, muon-spin-rotation, and neutron scattering. Under different conditions, however, the pancake vortices in each layer move independently of the other layers, and the system acts like a stack of independent thin film superconductors. Such two-dimensional (2D) behavior has also been seen in transformer experiments. Thus in layered superconductors two different effective dimensionalities of the vortex pancake lattice may appear, each with different characteristic properties. We use simulations of the exact magnetic interactions between pancakes in different layers to study the properties of these systems.

Preprints:

1. Metastable and transient effects in vortex matter near a disorder driven transition
   C.J. Olson, C. Reichhardt, R.T. Scalettar, G.T. Zimanyi, and N. Gronbech-Jensen
   cond-mat/0006172
   Phys. Rev. B 67 184523 (2003).
   We examine metastable and transient effects both above and below the first-order disorder driven decoupling line in a 3D simulation of magnetically interacting pancake vortices. We observe pronounced transient and history effects as well as supercooling and superheating between the ordered and disordered phases. In the disordered supercooled state as a function of DC driving, reordering occurs through the formation of growing moving channels of the ordered phase. We find that hysteresis in V(I) is strongly dependent on the proximity to the decoupling transition line.

Papers:

1. Disordering transitions in vortex matter: Peak effect and phase diagram
   C.J. Olson, C. Reichhardt, R.T. Scalettar, G.T. Zimanyi, and N. Gronbech-Jensen
   Physica C 384 143 (2003).
   Online version
   
2. Hysteretic depinning and dynamical melting for magnetically interacting vortices in disordered layered superconductors
   C.J. Olson, C. Reichhardt, and V.M. Vinokur
   Phys. Rev. B 64, 140502(R) (2001).
   Online version

3. Vortices freeze like window glass: the vortex molasses scenario
   C. Reichhardt, A. van Otterlo and G.T. Zimanyi
   Phys. Rev. Lett 84, 1994 (2000).
   Online version

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Last Modified: 6/1/02