Complex States, Emergent Phenomena & Superconductivity in Intermetallic & Metal-like Compounds
Kyuil Cho, Abhishek Pandey
The specific scientific question to be addressed by this Project is—can we develop, discover, understand and ultimately control, and predictably modify new and extreme examples of complex states, emergent phenomena, and superconductivity? Materials manifesting clear or compelling examples (or combinations) of superconductivity, strongly correlated electrons, quantum criticality, and exotic, bulk magnetism are of particular interest given their potential to lead to revolutionary steps forward in our understanding of their complex, and potentially energy relevant, properties. Experiment and theory are implemented synergistically. The experimental work consists of new materials development and crystal growth, combined with detailed and advanced measurements of microscopic, thermodynamic, and transport properties, as well as electronic structure, at extremes of pressure, temperature, magnetic field and resolution. The theoretical work focuses on modeling transport, thermodynamic and spectroscopic properties using world-leading, phenomenological approaches to superconductors and modern quantum many-body theory.
The ability to address these questions is illustrated by this group’s past work on many of the key systems and phenomena that have defined this field over the past decades: High Tc oxide, RNi2B2C and MgB2 superconductivity, Ce-, Yb- and transition metal-based heavy fermions, quantum criticality, quasicrystals, spin glasses, spin ladders / spin chains, vortex and domain pattern formation, ferromagnetism and metamagnetism.
- Design and growth (P. C. Canfield, S. Bud’ko, D. C. Johnston, J. Schmalian,V. Kogan)
- Advanced Characterization (S. Bud’ko, Y. Furukawa, A. Kaminski, R. Prozorov, M. Tanatar)
- Theory and modeling (J. R. Clem, V. Kogan, J. Schmalian)
Pratt D K; Zhao Y; Kimber S A J; Hiess A; Argyriou D N; Broholm C; Kreyssig A; Nandi S; Bud'ko S L; Ni N; Canfield P C; McQueeney R J; Goldman A I . 2009. Suppression of antiferromagnetic spin fluctuations in the collapsed phase of CaFe2As2. Physical Review B. 79:060510.
Bud'ko S L; Ni N; Nandi S; Schmiedeshoff G M; Canfield P C . 2009. Thermal expansion and anisotropic pressure derivatives of T-c in Ba(Fe1-xCox)(2)As-2 single crystals. Physical Review B. 79:05425.
Kreyssig A; Prozorov R; Dewhurst C D; Canfield P C; McCallum R W; Goldman A I . 2009. Probing Fractal Magnetic Domains on Multiple Length Scales in Nd2Fe14B. Physical Review Letters. 102:047204.
Kondo T; Khasanov R; Takeuchi T; Schmalian J; Kaminski A . 2009. Competition between the pseudogap and superconductivity in the high-T-c copper oxides. Nature. 457:296-300.
Yu W; Aczel A A; Williams T J; Bud'ko S L; Ni N; Canfield P C; Luke G M . 2009. Absence of superconductivity in single-phase CaFe2As2 under hydrostatic pressure. Physical Review B. 79:020511.
Connolly M R; Milosevic M V; Bending S J; Clem J R; Tamegai T . 2009. Continuum vs. discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+delta disks. Epl. 85:17008.
Szabo P; Pribulova Z; Pristas G; Bud'ko S L; Canfield P C; Samuely P . 2009. Evidence for two-gap superconductivity in Ba0.55K0.45Fe2As2 from directional point-contact Andreev-reflection spectroscopy. Physical Review B. 79:012503.
Dugdale S B; Utfeld C; Wilkinson I; Laverock J; Major Z; Alam M A; Canfield P C . 2009. Fermi surfaces of rare-earth nickel borocarbides. Superconductor Science & Technology. 22:014003.
Goldman A I; Kreyssig A; Prokes K; Pratt D K; Argyriou D N; Lynn J W; Nandi S; Kimber S A J; Chen Y; Lee Y B; Samolyuk G; Leao J B; Poulton S J; Bud'ko S L; Ni N; Canfield P C; Harmon B N; McQueeney R J . 2009. Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single-crystal neutron and x-ray diffraction investigation. Physical Review B. 79:024513.