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)
Goko T; Aczel A A; Baggio-Saitovitch E; Bud'ko S L; Canfield P C; Carlo J P; Chen G F; Dai P C; Hamann A C; Hu W Z; Kageyama H; Luke G M; Luo J L; Nachumi B; Ni N; Reznik D; Sanchez-Candela D R; Savici A T . 2009. Superconducting state coexisting with a phase-separated static magnetic order in (Ba,K)Fe2As2, (Sr,Na)Fe2As2, and CaFe2As2. Physical Review B. 80:024508.
Duguet T; Unal B; de Weerd M C; Ledieu J; Ribeiro R A; Canfield P C; Deloudi S; Steurer W; Jenks C J; Dubois J M; Fournee V; Thiel P A . 2009. Twofold surface of the decagonal Al-Cu-Co quasicrystal. Physical Review B. 80:024201.
Martin C; Tillman M E; Kim H; Tanatar M A; Kim S K; Kreyssig A; Gordon R T; Vannette M D; Nandi S; Kogan V G; Bud'ko S L; Canfield P C; Goldman A I; Prozorov R . 2009. Nonexponential London Penetration Depth of FeAs-Based Superconducting RFeAsO0.9F0.1 (R=La, Nd) Single Crystals. Physical Review Letters. 102:247002.
McCallum R W; Yan J Q; Rustan G E; Mun E D; Singh Y; Das S; Nath R; Bud'ko S L; Dennis K W; Johnston D C; Canfield P C; Kramer M J; Kreyssig A; Lograsso T A; Goldman A I . 2009. In situ high energy x-ray synchrotron diffraction study of the synthesis and stoichiometry of LaFeAsO and LaFeAsO1-xFy. Journal of Applied Physics. 105:123912.
Colombier E; Bud'ko S L; Ni N; Canfield P C . 2009. Complete pressure-dependent phase diagrams for SrFe2As2 and BaFe2As2. Physical Review B. 79:224518.
Hahn S E; Lee Y; Ni N; Canfield P C; Goldman A I; McQueeney R J; Harmon B N; Alatas A; Leu B M; Alp E E; Chung D Y; Todorov I S; Kanatzidis M G . 2009. Influence of magnetism on phonons in CaFe2As2 as seen via inelastic x-ray scattering. Physical Review B. 79:220511.
Bud'ko S L; Ni N; Canfield P C . 2009. Jump in specific heat at the superconducting transition temperature in Ba(Fe1-xCox)(2)As-2 and Ba(Fe1-xNix)(2)As-2 single crystals. Physical Review B. 79:220516.
Zhang J H; Sknepnek R; Fernandes R M; Schmalian J . 2009. Orbital coupling and superconductivity in the iron pnictides. Physical Review B. 79:220502.
Kimber S A J; Kreyssig A; Zhang Y Z; Jeschke H O; Valenti R; Yokaichiya F; Colombier E; Yan J; Hansen T C; Chatterji T; McQueeney R J; Canfield P C; Goldman A I; Argyriou D N . 2009. Similarities between structural distortions under pressure and chemical doping in superconducting BaFe2As2. Nature Materials. 8:471-475.