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Lessux, G. G.*; Sakai, Hironori; Hattori, Taisuke*; Tokunaga, Yo; Kambe, Shinsaku; Kuhns, P. L.*; Reyes, A. P.*; Thompson, J. D.*; Pagliuso, P. G.*; Urbano, R. R.*
Physical Review B, 101(16), p.165111_1 - 165111_6, 2020/04
Times Cited Count:7 Percentile:42.63(Materials Science, Multidisciplinary)CeRhIn is a Kondo-lattice prototype in which a magnetic field
31T induces an abrupt Fermi-surface (FS) reconstruction and pronounced in-plane electrical transport anisotropy all within its antiferromagnetic state. Here we report low-temperature nuclear magnetic resonance (NMR) measurements revealing a pronounced decrease in the
In formal Knight shift, without changes in crystal or magnetic structures, of CeRhIn
at fields (
) spanning
. We discuss the emergent state above
in terms of a change in Ce's 4
orbitals that arises from field-induced evolution of crystal-electric field (CEF) energy levels. This change in orbital character enhances hybridization between the 4
and the conduction electrons that leads ultimately to an itinerant quantum-critical point at
50T.
Sakai, Hironori; Urbano, R. R.*; Tokunaga, Yo; Kambe, Shinsaku; Suzuki, Michito; Kuhns, P. L.*; Reyes, A. P.*; Tobash, P. H.*; Ronning, F.*; Bauer, E. D.*; et al.
Physical Review Letters, 112(23), p.236401_1 - 236401_5, 2014/06
Times Cited Count:7 Percentile:48.71(Physics, Multidisciplinary)Very high field Si-NMR measurements using a fully
Si-enriched URu
Si
single crystal were carried out in order to microscopically investigate the "hidden order" (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the
Si shift,
. Moreover, a strong enhancement of
develops near a critical field
T, and the
Si-NMR signal disappears suddenly at
, indicating the total suppression of the HO state. Nevertheless, a weak and shifted
Si-NMR signal reappears for fields higher than
at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.
Bauer, E. D.*; Yang, Y.-F.*; Capan, C.*; Urbano, R. R.*; Miclea, C. F.*; Sakai, Hironori; Ronning, F.*; Graf, M. J.*; Balatsky, A. V.*; Movshovich, R.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 108(17), p.6857 - 6861, 2011/04
Times Cited Count:36 Percentile:82.17(Multidisciplinary Sciences)Here, we report a manifestation of electronic inhomogeneity in a strongly correlated -electron system, using CeCoIn
as an example. A thermodynamic analysis of its superconductivity, combined with nuclear quadrupole resonance measurements, shows that nonmagnetic impurities (Y, La, Yb, Th, Hg, and Sn) locally suppress unconventional superconductivity, generating an inhomogeneous electronic "Swiss cheese" due to disrupted periodicity of the Kondo lattice. Our analysis may be generalized to include related systems, suggesting that electronic inhomogeneity should be considered broadly in Kondo lattice materials.
Mounce, A. M.*; Oh, S.*; Mukhopadhyay, S.*; Halperin, W. P.*; Reyes, A. P.*; Kuhns, P. L.*; Fujita, Kazuhiro*; Ishikado, Motoyuki; Uchida, Shinichi*
Nature Physics, 7(2), p.125 - 128, 2011/02
Times Cited Count:7 Percentile:47.06It has been predicted that superconducting vortices should be electrically charged and that this effect is particularly enhanced for high-temperature superconductors. Hall effect and nuclear magnetic resonance (NMR) experiments suggest the existence of charge accumulation in the vortex core, but the effects are small and the interpretation controversial. Here we show that the Abrikosov vortex lattice, characteristic of the mixed state of superconductors, will become unstable at a sufficiently high magnetic field if there is charge trapped on the vortex core. Our NMR measurements of the magnetic fields generated by vortices in BiSr
CaCu
O
single crystals provide evidence for an electrostatically driven vortex lattice reconstruction with the magnitude of charge on each vortex pancake of
, depending on doping, in line with theoretical estimates.
Mounce, A. M.*; Oh, S.*; Mukhopadhyay, S.*; Halperin, W. P.*; Reyes, A. P.*; Kuhns, P. L.*; Fujita, Kazuhiro*; Ishikado, Motoyuki; Uchida, Shinichi*
Physical Review Letters, 106(5), p.057003_1 - 057003_4, 2011/02
Times Cited Count:8 Percentile:50.53(Physics, Multidisciplinary)Competition with magnetism is at the heart of high-temperature superconductivity, most intensely felt near a vortex core. To investigate vortex magnetism we have developed a spatially resolved probe based upon NMR spin-lattice-relaxation spectroscopy. With this approach we have found a spin-density wave associated with the vortex core in BiSr
CaCu
O
, similar to checkerboard patterns in the local density of electronic states reported from scanning tunneling microscope experiments. We have determined both the spin-modulation amplitude and decay length from the vortex core in fields up to
= 30 T.
Sakai, Hironori; Urbano, R. R.*; Tokunaga, Yo; Kambe, Shinsaku; Kuhns, P. L.*; Reyes, A. P.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
no journal, ,
In order to microscopically investigate what happens around 22 T and just above
36 T in the lowest temperature, we have performed
Si-NMR shift measurement using a
Si-fully-enriched single crystal of URu
Si
. We have found a shift anomaly around 22 T and a critical increase toward
36 T, corresponding to a slight change of total density of states (DOS) at
22 T and increase of DOS toward
36 T. Although the
Si-NMR signal was lost by field sweeping just above
36 T at the lowest temperature, the
Si-NMR spectrum has been successfully obtained at 4.2 K in the magnetic phase just above
36 T. From the spectral shape, we will discuss a possible magnetic structure in the magnetic phase.
Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Urbano, R. R.*; Kuhns, P. L.*; Reyes, A. P.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
no journal, ,
The heavy fermion superconductor URuSi
with
K shows the "hidden order" at
K. Below 1 K, it shows a first-order-transition at
T from the hidden order phase to the magnetically ordered phase. The
-
phase diagram for URu
Si
above 35 T is known to be complicated but the details in the each phase above 35 T are unknown. We have been investigating the electronic state by means of
Si-NMR in the higher field. The NMR experiment was done at National High Magnetic Field Laboratory (Tallahassee, FL, U.S.A.).