A5012965104- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Acoustic Wave Resonator Technologies
- Inorganic Chemistry and Materials
- Atomic and Subatomic Physics Research
- Quantum Chromodynamics and Particle Interactions
- Magnetic properties of thin films
- Topological Materials and Phenomena
- Photonic Crystals and Applications
- Advanced Chemical Physics Studies
- Magneto-Optical Properties and Applications
- Superconductivity in MgB2 and Alloys
- Electronic and Structural Properties of Oxides
- Magnetic Properties of Alloys
- Ultrasonics and Acoustic Wave Propagation
- Theoretical and Computational Physics
- Seismology and Earthquake Studies
- Advanced Materials Characterization Techniques
- Multiferroics and related materials
- Nuclear Materials and Properties
Binghamton University
2016-2022
Princeton University
2010-2014
Max Planck Institute for Solid State Research
2008-2010
Technical University of Munich
2008
Brookhaven National Laboratory
2008
Max Planck Society
2006-2007
Besides superconductivity, copper-oxide high temperature superconductors are susceptible to other types of ordering. We use scanning tunneling microscopy and resonant elastic x-ray scattering measurements establish the formation charge ordering in high-temperature superconductor Bi2Sr2CaCu2O8+x. Depending on hole concentration, this system occurs with same period as those found Y-based or La-based cuprates, displays analogous competition superconductivity. These results indicate similarity...
Heavy electronic states originating from the f atomic orbitals underlie a rich variety of quantum phases matter. We use scale imaging and spectroscopy with scanning tunneling microscope to examine novel that emerge uranium in URu(2)Si(2). find that, as temperature is lowered, partial screening electrons' spins gives rise spatially modulated Kondo-Fano resonance maximal between surface U atoms. At T = 17.5 K, URu(2)Si(2) known undergo second-order phase transition Kondo lattice state into...
The study of correlated electronic systems from high-T c cuprates to heavy-fermion continues motivate the development experimental tools probe phenomena in new ways and with increasing precision. In past two decades, spectroscopic imaging scanning tunneling microscopy has emerged as a powerful technique. combination high energy spatial resolutions provided by this technique reveals unprecedented detail properties strongly metals superconductors. This review examines specific experiments,...
The momentum and temperature dependence of the lifetimes acoustic phonons in elemental superconductors lead niobium were determined by resonant spin-echo spectroscopy with neutrons. In both elements, superconducting energy gap extracted from these measurements was found to converge sharp anomalies originating Fermi-surface nesting (Kohn anomalies) at low temperatures. results indicate electron many-body correlations beyond standard theoretical framework for conventional superconductivity. A...
Electronic nematic phases have been proposed to occur in various correlated electron systems and were recently claimed detected scanning tunneling microscopy (STM) conductance maps of the pseudogap states cuprate high-temperature superconductor ${\text{Bi}}_{2}{\text{Sr}}_{2}{\text{CaCu}}_{2}{\text{O}}_{8+\ensuremath{\delta}}$ (Bi-2212). We investigate influence anisotropic STM tip structures on such measurements establish, with a model calculation, presence interference effect within an...
Neutron resonance spin-echo spectroscopy was used to monitor the temperature evolution of linewidths transverse acoustic phonons in lead across superconducting transition temperature, $T_c$, over an extended range Brillouin zone. For with energies below energy gap, a linewidth reduction maximum amplitude $\sim 6 \mu$eV observed $T_c$. The electron-phonon contribution phonon lifetime extracted from these data is satisfactory overall agreement {\it ab-initio} lattice-dynamical calculations,...
Abstract Uranium compounds can manifest a wide range of fascinating many-body phenomena, and are often thought to be poised at crossover between localized itinerant regimes for 5 f electrons. The antiferromagnetic dipnictide USb 2 has been recent interest due the discovery rich proximate phase diagrams unusual quantum coherence phenomena. Here, linear-dichroic X-ray absorption elastic neutron scattering used characterize electronic symmetries on uranium in isostructural UBi . Of these two...
Abstract Search for novel electronically ordered states of matter emerging near quantum phase transitions is an intriguing frontier condensed physics. In ruthenates, the interplay between Coulomb correlations among 4 d electronic and their spin-orbit interactions, lead to complex forms phenomena. Here we investigate double layered Sr 3 (Ru 1− x Mn ) 2 O 7 its doping-induced transition from a metal antiferromagnetic Mott insulator. Using spectroscopic imaging with scanning tunneling...
In solids containing elements with f-orbitals, the interaction between f-electron spins and those of itinerant electrons leads to development low-energy fermionic excitations a heavy effective mass. These are fundamental appearance unconventional superconductivity observed in actinide- lanthanide-based compounds. We use spectroscopic mapping scanning tunneling microscope detect emergence lowering temperature Ce- U-based fermion demonstrate sensitivity process composite nature these...
Gapping of Dirac surface states through time reversal symmetry breaking may realize the axion insulator state in condensed matter. Despite tremendous efforts, only a few material systems fall into this category intrinsic magnetic topological insulators. Recent theoretical calculations proposed antiferromagnetic (AFM) ${\mathrm{EuIn}}_{2}{\mathrm{As}}_{2}$ to be topologically nontrivial with gapped states. Here we use scanning tunneling microscopy and spectroscopy complemented...
Recently we have used spectroscopic mapping with the scanning tunneling microscope to probe modulations of electronic density states in single crystals high temperature superconductor Bi2Sr2CaCu2O8+d (Bi-2212) as a function [C. V. Parker et al., Nature (London) 468, 677 (2010)]. These measurements showed Cu-O bond-oriented that form below pseudogap temperature-dependent energy dispersion displaying different behaviors superconducting and states. Here demonstrate quasiparticle scattering off...
Kondo lattice emerges from deep within the antiferromagnetic phase of a heavy fermion, driven by selective sub-orbitals.
Abstract Magnetic fluctuations induced by geometric frustration of local Ir-spins disturb the formation long-range magnetic order in family pyrochlore iridates. As a consequence, Pr 2 Ir O 7 lies at tuning-free antiferromagnetic-to-paramagnetic quantum critical point and exhibits an array complex phenomena including Kondo effect, biquadratic band structure, metallic spin liquid. Using spectroscopic imaging with scanning tunneling microscope, complemented machine learning, density functional...
TRISP is a novel high-resolution neutron spectrometer, combining the triple axis and resonance spin echo (NRSE) techniques. The design of optimized for study intrinsic linewidths elementary excitations (phonons, magnons) with an energy resolution in μeV region over broad range momentum transfers [1 Keller, T., Habicht, K., Klann, H., Ohl, M., Schneider, H. Keimer, B. 2002. Appl. Phys. A, 74: S332[Crossref], [Web Science ®] , [Google Scholar]]. Compared to conventional spectrometers (TAS),...
Layered material structures play a key role in enhancing electron-electron interactions to create correlated metallic phases that can transform into unconventional superconducting states. The quasi-two-dimensional electronic properties of such compounds are often inferred indirectly through examination bulk properties. Here we use scanning tunneling microscopy directly probe cross-section the states heavy fermion superconductor CeCoIn5. Our measurements reveal strong confined nature...
Resonant x-ray scattering (RXS) has recently become an increasingly important tool for the study of ordering phenomena in correlated electron systems. Yet, interpretation RXS experiments remains theoretically challenging because complexity cross section. Central to this debate is recent proposal that impurity-induced Friedel oscillations, akin quasi-particle interference signals observed with a scanning tunneling microscope (STM), can lead peaks experiments. The possibility properties be...
Kondo hybridization in partially filled f-electron systems conveys a significant amount of electronic states sharply near the Fermi energy leading to various instabilities from superconductivity exotic orders. UGe2 is 5f heavy fermion system, where interrupted by formation two ferromagnetic phases below second order transition Tc∼52K and crossover Tx∼32K. These are concomitantly related spin-triplet that only emerges persists inside magnetically ordered phase at high pressure. The origin how...