September 6 - 4:00pm Phys 223
(Coffee at 3:30p.m. in room 242)
Argonne National Laboratory
Materials Science Division
Magnetic fields penetrate superconductors as quantized tubes of flux surrounded by circulating supercurrents. These "vortices" interact via repulsive Lorentz forces and form an ordered lattice at low temperatures. At high temperatures in the cuprate superconductors, the lattice melts due to thermal energy, much as ice melts to water. Pinning defects disorder the lattice phases, producing glassy states. The talk will introduce these phases of "vortex matter," and then describe novel transport experiments that reveal the motion of the lattice and liquid phases under a shear stress.