Two recent publications involving neutron scattering experiments performed at the NIST Center for Neutron Research have been highlighted in the 2015 NCNR Annual Report. The studies, involving a multi-disciplinary collaboration between CNAM members J. Paglione (physics), E.E. Rodriguez (chemistry) and NIST Fellow J.W. Lynn, are focused on superconductivity and magnetism in iron-based materials and the half-Heusler ternary system.
This year's W. J. Carr Lecture Series on Superconductivity and Advanced Materials will be presented by Prof. Arthur Hebard from the University of Florida. Prof Hebard's research interests are focused on the fabrication and characterization of thin-film structures and are based on the recognition that unusual physical phenomena occur in restricted dimensions and at interfaces, for instance in magnetic and superconducting properties. His discoveries have been recognized by the American Physical Society’s award of the 2015 Oliver E. Buckley Condensed Matter Physics Prize to Hebard and collaborators “for discovery and pioneering investigations of the superconductor-insulator transition, a paradigm for quantum phase transitions.”
A Technical Seminar will be given on Monday, April 25 at 4pm in Toll 1201 (more info here), followed by a special Department Colloquium at 4pm in 1410 Toll (more info here).
Led by CNAM faculty member Prof. Stephen Anlage, University of Maryland physicists have developed a new cloaking material that can become transparent to microwave radiation with the flip of a switch. Because many wireless communication devices rely on microwaves, the new material could be used to design more efficient communications networks. The new material can be selectively tuned to respond to a wide range of microwave wavelengths, making it more versatile than many previous attempts at cloaking technology. The achievement is described in Physical Review X (2015) and featured on the Physics Department News Feed.
First predicted in 2010 by M. Dzero, V. Galitski and colleagues, the Topological Kondo Insulator (TKI) is a fascinating realization of the 3D topological insulator state in a strongly correlated "Kondo" insulator. Samarium Hexaboride, the archetype Kondo insulator, is an ideal candidate for realizing this exotic state of matter, with hybridization between itinerant conduction electrons and localized f-electrons driving an insulating gap and metallic surface states at low temperatures. SmB6 has been under scrutiny for over 45 years due to peculiar low temperature properties, which have only recently been suggested to arise due to the presence of topologically protected metallic surface states. In an new study led by Dr. Yasuyuki Nakajima in the Center for Nanophysics and Advanced Materials, the topological nature of metallic surface states in SmB6 was investigated by exploiting the existance of a novel surface-born ferromagnetic state and studying its effect on ultra-low temperature magnetotransport properties. Nakajima and co-workers report evidence of one-dimensional surface transport with a quantized conductance value of e2/h originating from the chiral edge channels of ferromagnetic domain walls, providing the strongest evidence to date that topologically non-trivial surface states exist in SmB6.
Read the recently published Letter entitled "One-dimensional edge state transport in a topological Kondo insulator" in Nature Physics (Nov 2015).
