Electronic nematic states, characterized by broken rotational symmetry, are prevalent in correlated materials. In most iron-based superconductors, the nematic anisotropy aligns with the Fe-Fe direction of the iron square lattice. However, recent investigations propose a unique form of nematicity oriented along the diagonal Fe-As direction in heavily hole-doped ( or Cs).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 2022
SignificanceThe notion of the quantum critical point (QCP) is at the core of modern condensed matter physics. Near a QCP of the symmetry-breaking order, associated quantum-mechanical fluctuations are intensified, which can lead to unconventional superconductivity. Indeed, dome-shaped superconducting phases are often observed near the magnetic QCPs, which supports the spin fluctuation-driven superconductivity.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2020
Electronic nematicity, a correlated state that spontaneously breaks rotational symmetry, is observed in several layered quantum materials. In contrast to their liquid-crystal counterparts, the nematic director cannot usually point in an arbitrary direction (XY nematics), but is locked by the crystal to discrete directions (Ising nematics), resulting in strongly anisotropic fluctuations above the transition. Here, we report on the observation of nearly isotropic XY-nematic fluctuations, via elastoresistance measurements, in hole-doped Ba Rb FeAs iron-based superconductors.
View Article and Find Full Text PDFBackground And Aim: The pathological features of non-alcoholic steatohepatitis (NASH) have not been determined, so fundamental treatment has not been established. Adipose-tissue-derived stromal/stem cells (ADSCs) are beneficial for repair/regenerative therapy of impaired organs because of their immuno-modulatory capability. In this study, we assessed how liver damage progresses during the early development phase of the murine NASH model and investigated whether ADSCs are preventatively efficacious against the fibrosis progression of NASH.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2016
In most unconventional superconductors, the importance of antiferromagnetic fluctuations is widely acknowledged. In addition, cuprate and iron-pnictide high-temperature superconductors often exhibit unidirectional (nematic) electronic correlations, including stripe and orbital orders, whose fluctuations may also play a key role for electron pairing. In these materials, however, such nematic correlations are intertwined with antiferromagnetic or charge orders, preventing the identification of the essential role of nematic fluctuations.
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