Mag. interfaces
Mag. nanostructures
Magnetic domain walls 
Two-band superconductivity 
Mag. heterostructuresMark Rzchowski
Professor of Physics, University of Wisconsin-MadisonResearch Area: Experimental Condensed Matter Physics
Specialty: Magnetic nanostructures, scanning probe spectroscopy
Postdoc: Harvard University Physics, 1988-1991
Ph.D Stanford University, 1988
A.B. Washington University in St. Louis, 1982
Physics Department
University of Wisconsin-Madison
1150 University Ave., Madison, WI 53706
rzchowski@physics.wisc.edu
608-265-2876 (ph)
608-265-2334 (fax)
| Interfaces in novel magnetic materials One of the most exciting aspects of current research on next-generation electronic heterostructures focuses on the manipulation of electron spin, rather than only electrical charge. Since the magnetic length scale is so short, the material at a heterostructure interface is electronically different from the bulk layers, and can in fact control the transport properties through the device. This becomes particularly interesting in novel strongly-correleated materials. More.... |
Domain walls in strongly correlated materials Walls between magnetic domains of different orientations have been investigated for many decades. The magnetic structure, the nanoscale size dependence, and electrical thermal scattering are reasonably well understood in many magnetic materials. But in strongly correlated systems, the magnetization gradient at the domain wall can alter the electronic structure of the material, for instance causing an insulating barrier to appear. More... |
| Transport in magnetic nanostructures When the size of a magnetic material reaches nanoscale dimensions, the individual spins often no longer form a clear domain structure with regions of parallel spins separated by magnetic domain walls. But rather the bulk of the spins have gradually changing orientiations, reminiscent of those in a magnetic domain wall. These unusual orientations can dramatically effect the coupling across magnetic interfaces, and also the transport through magnetic nanostructures. More... |
MgB2: a two-band superconductor MgB2, a 40K superconductor discovered in 2001, has the unique honor of possessing two almost orthogonal bands that cross the Fermi surface, both of whose electrons become superconducting with different interaction strengths. This leads to two superconducting gaps, two different vortex core sizes, and two different band critical currents - essentially two distinct superconductors in the same spatial location. Low temperature scanning tunneling spectroscopy reveals the gap structure and the band symmetry. More... |