Related papers: C-axis lattice dynamics in Bi-based cuprate superc…
Single crystals of the layered superconductor Bi2Sr2(Ca1-xLax)Cu2O8+d were successfully grown out by a self-flux method. Upon La-doping, the c-axis contracts but the structure remains stable up to the critical concentration xc, above which…
The formula frequently used to describe the c-axis infrared response of the coupled electron-phonon system of bilayer cuprate superconductors and providing important insights into the physics of these materials has been originally obtained…
Topologically protected surface states have garnered significant attention due to their robustness against perturbations and potential applications in optoelectronics. Bi2 Bi2Se3 is a topological semimetal composed of a 2D bismuthene sheet…
We investigate in the framework of linear response theory the complete phonon dispersion, phonon induced electronic charge response, electron-phonon interaction and dielectric and infrared properties of the high-temperature superconductors…
Formation of electron pairs is essential to superconductivity. For conventional superconductors, tunnelling spectroscopy has established that pairing is mediated by bosonic modes (phonons); a peak in the second derivative of tunnel current…
We use high resolution ARPES to study the resonant, collective excitation mode in the superconducting state of Bi2212. By collecting very high quality data we found new features in the self energy in the antinodal region, where the…
A kagome lattice of 3d transition metals hosts flat bands, Dirac fermions and saddle points. It provides a versatile platform for achieving topological superconductivity, anomalous Hall effect, unconventional density wave order and quantum…
Electron-boson coupling plays a key role in superconductivity for many systems. However, in copper-based high-temperature ($T_c$) superconductors, its relation to superconductivity remains controversial despite strong spectroscopic…
We investigate coherent lattice dynamics in optimally doped YBa$_2$Cu$_3$O$_{7-\delta}$ driven by ultrashort ($\sim$ 12 fs) near infrared (NIR) and near ultraviolet (NUV) pulses. Transient reflectivity experiments, performed at room…
Quasi-two-dimensional layered BiSe, a natural super-lattice with Bi2Se3-Bi2-Bi2Se3 units, has recently been predicted to be a dual topological insulator, simultaneously weak topological insulator as well as topological crystalline…
We use polarization-resolved Raman scattering to study lattice dynamics in NaFe$_{0.53}$Cu$_{0.47}$As single crystals. We identify 4 $A_{1g}$ phonon modes at 125, 172, 183 and 197 cm$^{-1}$, and 4 $B_{3g}$ phonon modes at 101, 138, 173, 226…
Since the discovery of cuprate, the origin of high-T$_c$ superconductivity has been an outstanding puzzle. Recently, high-T$_c$ superconductivity was observed in a bilayer nickelate La$_3$Ni$_2$O$_7$ under pressure, whose structure hosts…
We have examined the effect of a c(2x2) overlayer of CO on the surface phonons of the substrate, Cu(001), by applying the density functional perturbation theory with both the local (LDA) and the generalized-gradient (GGA) density…
A nodeless superconducting (SC) gap was reported in a recent scanning tunneling spectroscopy experiment of a copper-oxide monolayer grown on the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi2212) substrate [Y. Zhong {\it et al.}, Sci. Bull. {\bf…
Understanding what makes Bi$_2$Sr$_2$Ca$_1$Cu$_2$O$_x$ (Bi-2212) the only high critical current density ($J_c$), high temperature superconductor (HTS) capable of being made as a round wire (RW) is important intellectually because high $J_c$…
The phonon-mediated attractive interaction between carriers leads to the Cooper pair formation in conventional superconductors. Despite decades of research, the glue holding Cooper pairs in high-temperature superconducting cuprates is still…
We report here that magnetic fields of almost 34 T, far above the upper 24 T limit of Nb3Sn, can be generated using a multifilament round wire conductor made of the high temperature cuprate superconductor Bi2Sr2CaCu2O8-x (Bi-2212). A…
We have studied spectral evolution of the $E_u^1$ phonon line of a topological insulator Bi$_{2-x}$Sr$_x$Se$_3$ with temperature. Unlike the Raman-active phonons, the $E_u^1$ mode demonstrates softening upon cooling the crystal, and the…
The Bi2Sr2CaCu2O8+x high-temperature superconductor represents a natural metamaterial, composed of metallic CuO bilayers sandwiched between ionic BiO planes. Each pair of CuO bilayers forms an atomic-scale Josephson junction. Here we employ…
The lattice dynamics of members of the M2Mo6Se6 family of materials with guest ions M = K, Rb, Cs, In, and Tl has been studied using inelastic x-ray scattering and Raman spectroscopy at room temperature, as well as by ab-initio…