Stuart Field

Associate Professor
B.S., Stanford University, 1981; Ph.D., University of Chicago, 1986.

Vortices in Superconductors

The main focus of our research is in the area of superconductivity, with a particular interest in the static and dynamic properties of superconducting vortices and other magnetic flux structures. We use the technique of scanning Hall probe microscopy to image the vortices, allowing direct spatial information about their static configurations and dynamic flow patterns.

Recently, we have developed high-speed techniques to detect in real time the passage of individual flux tubes (containing ~100 flux quanta) beneath a fixed Hall sensor. Using this technique, we have measured for the first time clear evidence for the chaotic dynamics of driven flux bundles in a superconductor.

We are also working on the control of vortex motion at the single-vortex level. Using advanced lithographic techniques, we are preparing novel surface-modulated superconductors that will allow us to move vortices in controlled single steps. Such structures may find novel applications in precision metrology.

Selected Publications

• S. B. Field and G. Stan, "Chaotic Dynamics of Driven Flux Drops: A Superconducting "Dripping Faucet"," Phys. Rev. Lett. 100, 077001 (2008).

• G. Stan, S. B. Field, and J. M. Martinis, "CRITICAL FIELD FOR COMPLETE VORTEX EXPULSION FROM NARROW SUPERCONDUCTING STRIPS," Phys. Rev. Lett. 92, 097003 (2004).

• S. B. Field, S. S. James, J. Barentine, V. Metlushko, G. Crabtree, H. Shtrikman, B. Ilic, and S. R. J. Brueck, "VORTEX CONFIGURATIONS, MATCHING, AND DOMAIN STRUCTURE IN LARGE ARRAYS OF ARTIFICIAL PINNING CENTERS," Phys. Rev. Lett. 88, 067003 (2002).

• D. Davidovic, S. Kumar, D. H. Reich, J. Siegel, S. B. Field, R. Tiberio, R. Hey, and K. Ploog, "CORRELATIONS AND DISORDER IN ARRAYS OF MAGNETICALLY-COUPLED SUPERCONDUCTING RINGS," Phys. Rev. Lett. 76, 851 (1996).

Photo Gallery

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A Hall probe used in scanning Hall probe microscopy

Vortices in the presence of a periodic array of pinning centers

A bifurcation diagram for flux-tube dynamics