Related papers: Non-Conventional Critical Behavior and Q-dependent…
The cuprates exhibit a prominent charge-density-wave (CDW) instability with wavevector along [100], i.e., the Cu-O bond direction. Whereas CDW order is most prominent at moderate doping and low temperature, there exists increasing evidence…
Superconductivity emerges in $1T$-TiSe$_2$ when its charge density wave (CDW) order is suppressed by Cu intercalation or pressure. Since the CDW state is thought to be an excitonic insulator, an interesting question is whether the…
We report a comprehensive Raman study of the phonon behaviour in PdSe$_2$ in the temperature range of 5 K to 300 K. A remarkable change in the Raman spectrum is observed at 120 K: a significant enhancement of the out-of-plane phonon…
We report high-resolution inelastic x-ray measurements of the soft phonon mode in the charge-density-wave compound TiSe$_2$. We observe a complete softening of a transverse optic phonon at the L point, i.e. q = (0.5, 0, 0.5), at T ~…
The coexistence of charge density wave (CDW) and superconductivity in tantalum disulfide (2H-TaS$_2$) at ambient pressure, is boosted by applying hydrostatic pressures up to 30GPa, thereby inducing a typical dome-shaped superconducting…
We report temperature evolution of coherently excited acoustic and optical phonon dynamics in superconducting iron pnictide single crystal Ca(Fe_0.944Co_0.056)_2As_2 across the spin density wave transition at T_SDW ~ 85 K and…
Two-dimensional superconductors attract great interest both for their fundamental physics and for their potential applications, especially in the rapidly growing field of quantum computing. Despite intense theoretical and experimental…
Charge density wave (CDW) is a collective quantum phenomenon with a charge modulation in solids1-2. Condensation of electron and hole pairs with finite momentum will lead to such an ordered state3-7. However, lattice symmetry breaking…
We present a high energy-resolution inelastic x-ray scattering investigation of the soft phonon mode in the charge-density-wave system TbTe$_3$. We analyze our data based on lattice dynamical calculations using…
We investigate the quasiparticle relaxation and low-energy electronic structure in undoped SrFe_2As_2 exhibiting spin-density wave (SDW) ordering using optical pump-probe femtosecond spectroscopy. A remarkable critical slowing down of the…
We report measurements of the electrical resistivity and ac magnetic susceptibility of single crystalline LaPt$_2$Si$_2$ under pressure, in order to investigate the interplay of superconductivity and CDW order. LaPt$_2$Si$_2$ exhibits a…
$(TaSe_4)_2I$ is a well-studied quasi-one-dimensional compound long-known to have a charge-density wave (CDW) transition around 263 K. We argue that the critical fluctuations of the pinned CDW order parameter near the transition can be…
Extensive inelastic neutron scattering measurements of phonons on a single crystal of CaFe2As2 allowed us to establish a fairly complete picture of phonon dispersions in the main symmetry directions. The phonon spectra were also calculated…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…
We present an investigation of the lattice dynamics of the charge-density-wave compound 2H-NbSe2. We analyze the precise nature of the wave vector dependent electron-phonon coupling (EPC) and derive the bare dispersion of the…
Charge-density-wave (CDW) order and superconductivity often compete in low-dimensional materials, yet their interplay in Janus MXenes remains largely unexplored. Here, we present a comprehensive first-principles investigation of the…
Layered 1$T$-TiSe$_{2}$ has attracted much interest for the competition of charge density wave (CDW) and superconductivity in its bulk and even monolayer forms. Here we perform first-principles calculations of the electronic structure,…
The specific heat of two polymorphs of BaPd2As2 was measured. The ThCr2Si2-type polymorph (space group I4/mmm, $D_{4h}^{17}$, No. 139) is a previously reported superconductor with a transition temperature Tc $\simeq$ 3.5 K, while the…
High-resolution photoemission has been used to study the electronic structure of the charge density wave (CDW) and superconducting (SC) dichalcogenide, 2H- NbSe2. From the extracted self-energies, important components of the quasiparticle…
Phonon softening is a ubiquitous phenomenon in condensed matter systems which is often associated with charge density wave (CDW) instabilities and anharmonicity. The interplay between phonon softening, CDW and superconductivity is a topic…