Experimental Condensed Matter

Research Interests

Experimental properties of superconducting and magnetic properties of materials are carried out at low temperatures, high pressures and high magnetic fields. A first group of materials under study include rare earth, actinide and transition metal alloys and compounds, organic conductors and high temperature superconductors. Phenomena studied include heavy fermion and non-Fermi liquid effects, anomalous upper critical magnetic fields and "peak effect" in the magnetization of superconductors, highly anisotropic actinide compounds exhibiting metamagnetism, weak ferromagnetism or spin density wave states. A second group of materials under study include superconducting thin films patterned with lattices of artificial pinning centers such as antidots (holes), metallic or ferromagnetic dots. Associated phenomena studied include novel equilibrium magnetic vortex phases and the nonlinear magnetic response of the vortex phases to electromagnetic drives, nonlinear superfluid hydrodynamics and chaotic behavior of the superconducting mixed state. A third area of research involves development of superconducting levitation technologies for applications in bioreactors and stirrers for biopharmaceutical, biomedical and agricultural processes.

Postdoctoral Fellows

• Alexandre Terentiev

Graduate Students

• Byron Watkins
• Alexandre Kolomiets
• Sergej Kryukov

• V. Metlushko, U. Welp, G. Crabtree, R. Osgood, S. D. Bader, L. E. De Long, Zhao Zhang, S. R. J. Brueck, B. Ilic, K. Chung, and P. J. Hesketh, "New interstitial flux phases in superconducting niobium film with square lattices of artificial pinning centers," Phys. Rev. B 60 R12595 (1999)
• A. Terentiev, L. E. De Long, D. j. Morgan, J. B. Ketterson, and L. D. Cooley, "Periodic magnetization instabilities in a superconducting Nb film with square lattice of Ni dots," Phys. Rev. B 61 R9249 (2000)
• A. Terentiev, D. B. Watkins, L. E. De Long, D. J. Morgan and J. B. Ketterson, "Paramagnetic Relaxation and Wohlleben Effect in Field-Cooled Nb Thin Films", Phys. Rev. B 60, R761 (1999).
• L. Shlyk, J. C. Waerenborgh, P. Estrela, L. E. De Long, A. de Visser, and M. Almeida, "Non-Fermi-Liquid Behavior of U_3-xNi₃Sn_4-y Single Crystals", J. Phys.: Condens. Matter 11, 3525 (1999).
• A. V. Kolomiets, L. Havela, V. Sechovsky, L. E. De Long, D. B. Watkins and A. V. Andreev, "Non-Fermi Liquid Behaviour of UCoAl", Physica B 259, 415 (1999).
• V. V. Metlushko, L. E. De Long, M. Baert, E. Rosseel, M. J. Van Bael, K. Temst, V. V. Moschalkov and Y. Bruynseraede, "Supermatching Vortex Phases in Superconducting Thin Films with Antidot Lattices", Europhys. Lett. 41, 333 (1998).
• Junqing Zhang, L. E. De Long, V. Majidi and R. C. Budhani, "Nonlinear Dynamics of Magnetic Vortices in Single-Crystal and Ion-Damaged NbSe₂", Phys. Rev. B (Rapid Commun.) 53, R8851 (1996).