Related papers: Slow Electronic Dynamics in the Paramagnetic State…
We investigate the electronic states and the transport properties of the CoO2 plane in NaxCoO2 on the basis of the two-dimensional triangular lattice 11-band d-p model by using the fluctuation exchange approximation, where we consider the…
We report high-pressure $^{77}$Se NMR studies on FeSe single crystals that reveal a prominent inhomogeneous NMR linewidth broadening upon cooling, with the magnetic field applied along the tetragonal [110] direction. The data indicate the…
We present a SU(2) gauge theory of fluctuating magnetic order in the two-dimensional Hubbard model. The theory is based on a fractionalization of electrons in fermionic chargons and bosonic spinons. The chargons undergo N\'eel or spiral…
The $\rm Fe_{1+y}Te_{1-x}Se_x$\ single crystals with the various Se/Te ratios were studied by the microwave absorption and direct current resistivity measurements. The comparison of the microwave absorption data and the resistivity versus…
It has been a great challenge to explore many-body effects in heavy fermion systems with $ab$-$initio$ approaches. We computed the electronic structure of UTe$_{2}$ without purposive judgements, such as intentional selection of on-site…
A fragile ordered state can be easily tuned by various external parameters. When the ordered state is suppressed to zero temperature, a quantum phase transition occurs, which is often marked by the appearance of unconventional…
The effect of fluctuations on the nuclear magnetic resonance (NMR) relaxation rate, $W$, is studied in a complete phase diagram of a 2D superconductor above the upper critical field line $H_{c2}(T)$ . In the region of relatively high…
The macroscopic magnetizations of a RuSr2(Eu0.7Ce0.3)2Cu2O10+d sample were investigated. A ferromagnet-like transition occurs around T_M in the low-field magnetization. Highly nonlinear M(H), non-Curie-Weiss susceptibility, and slow…
Collective dynamics often play an important role in determining the stability of ground states for both naturally occurring materials and metamaterials. We studied the temperature dependent dynamics of antiferromagnetically ordered…
Neutron scattering experiments on a polycrystalline sample of the frustrated pyrochlore magnet Tb2Ti2O7, which does not show any magnetic order down to 50 mK, have revealed that it shows condensation behavior below 0.4 K from a thermally…
We investigate a spin reorientation transition (SRT) in ultrathin magnetic films by Monte-Carlo simulations. We assume that the lateral size of the film is relatively small and it has a single-domain structure. To gain insights into the…
In low-dimensional magnets, thermal agitation and spatial disorders generate strong spin fluctuations that suppress the long-range magnetic ordering. We develop an analytical equation for the equilibrium magnetization of two-dimensional…
Recently, superconductivity has been observed in twisted WSe$_2$ moir\'{e} structures (Xia et al., Nature 2024; Guo et al., Nature 2025). Its transition temperature is high, reaching a few percent of the Fermi temperature scale. Here, we…
We summarize the present status of the theories of spin fluctuations in dealing with the anomalous or non-Fermi liquid behavior and unconventional superconductivity in strongly correlated electron systems around their magnetic instabilities…
We report X-band EPR and $^{125}$Te and $^{77}$Se NMR measurements on single-crystalline superconducting FeSe$_{0.42}$Te$_{0.58}$ ($T_c$ = 11.5(1) K). The data provide evidence for the coexistence of intrinsic localized and itinerant…
When the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr3Ru2O7 can be tuned through quantum…
We report $^{75}$As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) studies on the superconductor Rb$_{2}$Cr$_{3}$As$_{3}$ with a quasi one-dimensional crystal structure. Below $T\sim$ 100 K, the spin-lattice…
Patterned nanostructures on the order of 200 nm $\times$ 200 nm of the itinerant ferromagnet ${\rm SrRuO_3}$ give rise to superparamagnetic behavior below the Curie temperature (${\rm \sim 150 \ K}$) down to a sample-dependent blocking…
The recent discovery of non-saturating giant positive magnetoresistance in Td-WTe2 has aroused great interest in this material. We have studied the structural, electronic and vibrational properties of bulk and few-layer Td-WTe2…
Taking into account the transverse gauge field fluctuations, which interact with composite fermions, we examine the finite temperature compressibility of the fermions as a function of an effective magnetic field $\Delta B = B - 2 n_e hc/e$…