636 research outputs found
Competition between spin ordering and superconductivity near the pseudogap boundary in La2âxSrxCuO4: Insights from NMR
When superconductivity is suppressed by high magnetic fields in La2âxSrxCuO4, striped antiferromagnetic (AFM) order becomes the magnetic ground state of the entire pseudogap regime, up to its end at the doping pâ [Frachet, Vinograd et al., Nat. Phys. 16, 1064 (2020)]. Glass-like freezing of this state is detected in 139La NMR measurements of the spin-lattice relaxation rate Tâ11. Here, we present a quantitative analysis of Tâ11 data in the hole-doping range p=x=0.12â0.171, based on the Bloembergen-Purcell-Pound (BPP) theory, modified to include statistical distribution of parameters arising from strong spatial inhomogeneity. We observe spin fluctuations to slow down at temperatures T near the onset of static charge order and, overall, the effect of the field B may be seen as equivalent to strengthening stripe order by approaching p=0.12 doping. In details, however, our analysis reveals significant departure from usual field-induced magnetic transitions. The continuous growth of the amplitude of the fluctuating moment with increasing B suggests a nearly-critical state in the Bâ0 limit, with very weak quasistatic moments possibly confined in small areas like vortex cores. Further, the nucleation of spin order in the vortex cores is shown to account quantitatively for both the value and the p dependence of a field scale characterizing bulk spin freezing. The correlation time of the fluctuating moment appears to depend exponentially on B/T (over the investigated range). This explains the timescale dependence of various experimental manifestations, including why, for transport measurements, the AFM moments may be considered static over a considerable range of B and T. These results make the high-field magnetic ground state up to pâ an integral part of the discussion on putative quantum criticality
Competition between spin ordering and superconductivity near the pseudogap boundary in La Sr CuO: Insights from NMR
Identification of Simple Compounds with Microtubule-Binding Activity That Inhibit Cancer Cell Growth with High Potency
Electronic reconstruction forming a -symmetric Dirac semimetal in CaRuO
Electronic band structures in solids stem from a periodic potential
reflecting the structure of either the crystal lattice or an electronic order.
In the stoichiometric ruthenate CaRuO, numerous Fermi surface
sensitive probes indicate a low-temperature electronic reconstruction. Yet, the
causality and the reconstructed band structure remain unsolved. Here, we show
by angle-resolved photoemission spectroscopy, how in CaRuO a
-symmetric massive Dirac semimetal is realized through a Brillouin-zone
preserving electronic reconstruction. This Dirac semimetal emerges in a
two-stage transition upon cooling. The Dirac point and band velocities are
consistent with constraints set by quantum oscillation, thermodynamic, and
transport experiments, suggesting that the complete Fermi surface is resolved.
The reconstructed structure -- incompatible with
translational-symmetry-breaking density waves -- serves as an important test
for band structure calculations of correlated electron systems
Pseudogap suppression by competition with superconductivity in La-based cuprates
We carried out a comprehensive high-resolution angle-resolved photoemission spectroscopy (ARPES) study of the pseudogap interplay with superconductivity in La-based cuprates. The three systems La2âxSrxCuO4, La1.6âxNd0.4SrxCuO4, and La1.8âxEu0.2SrxCuO4 display slightly different pseudogap critical points in the temperature versus doping phase diagram. We studied the pseudogap evolution into the superconducting state for doping concentrations just below the critical point. In this setting, near optimal doping for superconductivity and in the presence of the weakest possible pseudogap, we uncover how the pseudogap is partially suppressed inside the superconducting state. This conclusion is based on the direct observation of a reduced pseudogap energy scale and re-emergence of spectral weight suppressed by the pseudogap. Altogether these observations suggest that the pseudogap phenomenon in La-based cuprates is in competition with superconductivity for antinodal spectral weight
Pseudogap Suppression by Competition with Superconductivity in La-Based Cuprates
We have carried out a comprehensive high-resolution angle-resolved
photoemission spectroscopy (ARPES) study of the pseudogap interplay with
superconductivity in La-based cuprates. The three systems
LaSrCuO, LaNdSrCuO, and
LaEuSrCuO display slightly different pseudogap
critical points in the temperature versus doping phase diagram. We have studied
the pseudogap evolution into the superconducting state for doping
concentrations just below the critical point. In this setting, near optimal
doping for superconductivity and in the presence of the weakest possible
pseudogap, we uncover how the pseudogap is partially suppressed inside the
superconducting state. This conclusion is based on the direct observation of a
reduced pseudogap energy scale and re-emergence of spectral weight suppressed
by the pseudogap. Altogether these observations suggest that the pseudogap
phenomenon in La-based cuprates is in competition with superconductivity for
anti-nodal spectral weight
A numerical simulation analysis of the effect of the interface drag function on cluster evolution in a CFB riser gas-solid flow
Sour Taste Responses in Mice Lacking PKD Channels
The polycystic kidney disease-like ion channel PKD2L1 and its associated
partner PKD1L3 are potential candidates for sour taste receptors. PKD2L1 is
expressed in type III taste cells that respond to sour stimuli and genetic
elimination of cells expressing PKD2L1 substantially reduces chorda tympani
nerve responses to sour taste stimuli. However, the contribution of PKD2L1
and PKD1L3 to sour taste responses remains unclear.We made mice lacking PKD2L1 and/or PKD1L3 gene and investigated whole nerve
responses to taste stimuli in the chorda tympani or the glossopharyngeal
nerve and taste responses in type III taste cells. In mice lacking PKD2L1
gene, chorda tympani nerve responses to sour, but not sweet, salty, bitter,
and umami tastants were reduced by 25â45% compared with those
in wild type mice. In contrast, chorda tympani nerve responses in PKD1L3
knock-out mice and glossopharyngeal nerve responses in single- and
double-knock-out mice were similar to those in wild type mice. Sour taste
responses of type III fungiform taste cells (GAD67-expressing taste cells)
were also reduced by 25â45% by elimination of PKD2L1.These findings suggest that PKD2L1 partly contributes to sour taste responses
in mice and that receptors other than PKDs would be involved in sour
detection
Angiotensin-converting enzyme gene and retinal arteriolar narrowing: The Funagata Study
The purpose of this study is to determine whether the angiotensin-converting enzyme (ACE) gene polymorphism is associated with retinal arteriolar narrowing, a subclinical marker of chronic hypertension. The Funagata Study examined a population-based sample of Japanese aged 35+ years; 368 participants had both retinal vessel diameter measurements and ACE insertion/deletion (ACE I/D) polymorphism analyses performed. Assessment of retinal vessel diameter and retinal vessel wall signs followed the protocols used in the Blue Mountains Eye Study. ACE gene polymorphisms D/D, I/D and I/I were present in 34 (9.2%), 170 (46.2%) and 164 (44.5%) participants, respectively, distributed in HardyâWeinberg equilibrium. After multivariable adjustment, retinal arteriolar diameter was significantly narrower in subjects with the D/D genotype compared to subjects with I/D and I/I genotypes (mean difference â6.49âÎŒm, 95% confidence interval (CI): â12.86âÎŒm, â0.11âÎŒm). Our study suggests that the ACE I/D polymorphism may be associated with subclinical structural arteriolar changes related to chronic hypertension
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