A5079228892- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Rare-earth and actinide compounds
- Theoretical and Computational Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Condensed Matter Physics
- Quantum, superfluid, helium dynamics
- Magnetic and transport properties of perovskites and related materials
- Topological Materials and Phenomena
- Magnetic properties of thin films
University of Florida
2020-2024
Florida Museum of Natural History
2020
Bogoliubov Fermi surfaces (BFSs) are topologically protected regions of zero energy excitations in a superconductor whose dimension equals that the underlying normal state surface. Examples Hamiltonians exhibiting this ``ultranodal'' phase known to preserve charge-conjugation ($C$) and parity ($P$) but break time-reversal ($T$). In work, we provide examples model do not necessarily symmetry pattern have well-defined sign-changing Pfaffians yielding BFSs. While their topological character has...
Abstract Bogoliubov Fermi surfaces are contours of zero-energy excitations that protected in the superconducting state. Here we show multiband superconductors with dominant spin singlet, intraband pairing spin-1/2 electrons can undergo a transition to state if spin-orbit coupling, interband and time reversal symmetry breaking also present. These latter effects may be small, but drive topological for appropriate nodal structure intra-band pair. Such should display nonzero zero-bias density...
Several unconventional superconductors show indications of zero-energy excitations in the superconducting state consistent with existence a so-called Bogoliubov-Fermi surface (BFS). In particular, FeSe isovalently substituted S seems to acquire nonzero density states at zero energy low temperatures as system goes into tetragonal phase, previously proposed phenomenological theory assuming an anisotropic spin singlet pairing gap coexisting nonunitary interband triplet component. Here we search...
The iron-based superconductor FeSe isovalently substituted with S displays an abundance of remarkable phenomena that have not been fully understood, at the center which are apparent zero-energy excitations in superconducting state tetragonal phase. phenomenology has generally consistent proposal so-called ultranodal states where Bogoliubov Fermi surfaces present. Recently, nuclear magnetic resonance measurements seen unusually large upturns relaxation rate as temperature decreases to nearly...
The strange-metal phase of the cuprate high temperature superconductors, above where superconductivity sets in as a function temperature, is widely considered more exotic and mysterious than itself. Here, based upon detailed angle resolved photoemission spectroscopy measurements Bi$_2$Sr$_2$CaCu$_2$O$_8$$_+$$_δ$ over wide range doping levels, we present new unifying phenomenology for non-Fermi liquid normal-state interactions (scattering rates) nodal direction. This has continuously varying...
The iron-based superconductor FeSe isovalently substituted with S displays an abundance of remarkable phenomena that have not been fully understood, at the center which are apparent zero-energy excitations in superconducting state tetragonal phase.The phenomenology has generally consistent proposal so-called ultranodal states where Bogoliubov Fermi surfaces present.Recently, nuclear magnetic resonance measurements seen unusually large upturns relaxation rate as temperature decreases to...
Conventional superconductivity is robust against the addition of impurities unless are magnetic in which case quickly suppressed. Here we present a study cuprate superconductor Bi$_2$Sr$_2$Ca$_1$Cu$_2$O$_{8+δ}$ that intentionally doped with impurity, Fe. Through use our Tomographic Density States (TDoS) technique, find while superconducting gap magnitude essentially unaffected by inclusion iron, onset superconductivity, T$_{C}$, and pair-breaking rate strongly dependent correlated. These...
Several unconventional superconductors show indications of zero-energy excitations in the superconducting state consistent with existence a so-called Bogoliubov Fermi surface (BFS). In particular, FeSe doped S seems to acquire nonzero density states at zero energy low temperatures when into tetragonal phase, previously proposed phenomenological theory assuming an anisotropic spin singlet pairing gap coexisting nonunitary interband triplet component. Here we search for microscopic model that...