相关论文: Structural Phase Transition in the 2D Spin Dimer C…

Using an {\it ab initio} approach, we report a phonon soft mode in the tetragonal structure described by the space group $I4_{1}22$ of the $1$ K $5d$ superconductor Cd$_2$Re$_2$O$_7$. It induces an orthorhombic distortion to a crystal…

We have recently predicted and subsequently verified experimentally by specific heat measurements that EuTiO3 undergoes a structural phase transition at elevated temperature TS = 282 K. The origin of the phase transition has been attributed…

We use Raman scattering to study spin, charge, and lattice dynamics in various phases of Ca_{2-x}Sr_{x}RuO_{4}. With increasing substitution of Ca by Sr in the range 0 =< x < 0.2, we observe (1) evidence for an increase of the…

$\mathrm{Cu_2IrO_3}$ is among the newest layered honeycomb iridates and a promising candidate to harbor a Kitaev quantum spin liquid state. Here, we investigate the pressure and temperature dependence of its structure through a combination…

Sr2IrO4 exhibits a novel insulating state assisted by spin-orbit interactions. A series of polycrystalline samples of Sr2-xIrO4 have been synthesized. It is found that deep Sr-vacancies of Sr2-xIrO4 greatly reduce the rotation of IrO6…

The superconducting pyrochlore oxide Cd2Re2O7 (Tc = 1 K), which is now considered as a candidate of the spin-orbit-coupled metal, shows an inversion-symmetry-breaking structural transition at Ts1 = 200 K. Ts1 decreases with increasing…

High resolution X-ray scattering measurements on single crystal Tb2Ti2O7 reveal finite structural correlations at low temperatures. This geometrically frustrated pyrochlore is known to exhibit a spin liquid, or cooperative paramagnetic…

We report a structural transition found in Ca10(Ir4As8)(Fe2-xIrxAs2)5, which exhibits superconductivity at 16 K. The c-axis parameter is doubled below a structural transition temperature of approximately 100 K, while the tetragonal symmetry…

Single-crystal X-ray diffraction was employed to study the structural-electronic phase transition of IrTe$_2$ at approximately 270 K. The low-temperature structure was found to be a triclinic (space group $P\bar{1}$) characterized by the…

We investigated temperature dependent Raman spectra of the one-dimensional spin-ladder compound SrCu2O3. At low temperatures a two-magnon peak is identified at 3160+/-10 cm^(-1) and its temperature dependence analyzed in terms of a thermal…

The new quaternary iron arsenide-fluoride SrFeAsF with the tetragonal ZrCuSiAs-type structure was synthesized and the crystal structure was determined by X-ray powder diffraction (P4/nmm, a = 399.30(1), c = 895.46(1) pm). SrFeAsF undergoes…

The insulating ferrimagnet Cu2OSeO3 shows a rich variety of phases such as skyrmion lattice and helical magnetism controlled by interplay of different exchange interactions which can be tuned by external pressure. In this work we have…

BaFe2Se3 (Pnma, CsAg2I3-type structure), recently assumed to show superconductivity at ~ 11 K, exhibits a pressure-dependent structural transition to the CsCu2Cl3-type structure (Cmcm space group) around 60 kbar, as evidenced from…

We report the observation of magnetic superstructure in a magnetization plateau state of SrCu2(BO3)2, a frustrated quasi-two-dimensional quantum spin system. The Cu and B nuclear magnetic resonance (NMR) spectra at 35 mllikelvin indicate an…

We calculate the electron spin resonance (ESR) spectra of the quasi-two-dimensional dimer spin liquid SrCu2(BO3)2 as a function of magnetic field B. Using the standard Lanczos method, we solve a Shastry-Sutherland Hamiltonian with…

The ternary iron arsenide BaFe2As2 with the tetragonal ThCr2Si2-type structure exhibits a spin density wave (SDW) anomaly at 140 K, very similar to LaFeAsO, the parent compound of the iron arsenide superconductors. BaFe2As2 is a poor…

Two-dimensional (2D) topological insulators (TIs) hold promise for applications in spintronics based on the fact that the propagation direction of edge electrons of a 2D TI is robustly linked to their spin origination. Here, with the use of…

We present here temperature-dependent Raman, x-ray diffraction and specific heat studies between room temperature and 12 K on single crystals of spin-ice pyrochlore compound $Dy_2Ti_2O_7$ and its non-magnetic analogue $Lu_2Ti_2O_7$. Raman…

We report the observation of a frequency shift and splitting of the electron spin resonance (ESR) mode of the low-dimensional S=1/2 frustrated antiferromagnet Cs2CuCl4 in the spin-correlated state below the Curie-Weiss temperature 4 K but…

The 5d pyrochlore oxide superconductor Cd2Re2O7 (CRO) has attracted significant interest as a spin-orbit-coupled metal (SOCM) that spontaneously undergoes a phase transition to an odd-parity multipole phase by breaking the spatial inversion…