Related papers: Charge density wave and spin $1/2$ insulating stat…
The transition metal dichalcogenides 1T-TaS$_2$ and 1T-TaSe$_2$ have been extensively studied for the complicated correlated electronic properties. The origin of different surface electronic states remains controversial. We apply scanning…
Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum…
A density functional theory study of NbSe$_2$ single-layers in the normal non-modulated and the $3\times3$ CDW states is reported. We show that, in the single layer, the CDW barely affects the Fermi surface of the system, thus ruling out a…
The natural van der Waals heterostructure 4H$_b$-TaS$_2$ composed of alternating 1T- and 1H-TaS$_2$ layers serves as a platform for investigating the electronic correlations and layer-dependent properties of novel quantum materials. The…
Charge density waves (CDW) in single-layer 1$T$-MTe$_2$ (M= Nb, Ta) recently raised large attention because of the contrasting structural and physical behavior with the sulfide and selenide analogues. A first-principles study of fourteen…
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,…
A prototypical quasi-2D metallic compound, 1T-TaS_2 has been extensively studied due to an intricate interplay between a Mott-insulating ground state and a charge density-wave (CDW) order. In the low-temperature phase, 12 out of 13 Ta_{4+}…
We investigate the 1/3 monolayer $\alpha$-Pb/Si(111) surface by scanning tunneling spectroscopy (STS) and fully relativistic first-principles calculations. We study both the high-temperature $\sqrt{3}\times\sqrt{3}$ and low-temperature…
The $\sqrt{13}\times\sqrt{13}$ charge density wave state of the T polytype of MX$_2$ (M=Nb,Ta, X=S, Se) is known to host a half-filled flat band, which electronic correlations drive into a Mott insulating state. When T polytypes are coupled…
The basic and the charge density wave (CDW) structures of the monoclinic $NbS_3-II$ polymorph were studied by synchrotron x-ray diffraction, ab-initio calculation, simulation of electron diffraction patterns and by atomic-resolution…
We report a significant enhancement of superconducting transition temperature ($\textit{T}_\textrm{c}$) of transition metal dichalcogenide (TMD) superconductor $\textrm{NbTe}_2$ from 0.56 K to 2.8 K. Detailed x-ray structure analysis…
Electronic phases that lie outside the equilibrium ground state offer a route to explore competing configurations in correlated materials. In 1T-TaS2, ultrafast excitation accesses a metallic hidden phase that is distinct from the…
The interplay of different emergent phenomena -- superconductivity (SC) and domain formation -- appearing on different spatial and energy scales are investigated using high-resolution scanning tunneling spectroscopy (STS) in the…
We studied TbTe$_{3}$ using scanning tunneling microscopy (STM) in the temperature range of 298 - 355 K. As seen in previous STM measurements on RTe$_{3}$ compounds, our measurements detect a unidirectional charge density wave state (CDW)…
A new frontier in condensed matter physics is to stack atomically thin layered-materials with different properties and create intriguing phenomena which do not exist in any of the constituent layers. Transition metal dichalcogenide…
Properties of two-dimensional transition metal dichalcogenides are highly sensitive to the presence of defects in the crystal structure. A detailed understanding of defect structure may lead to control of material properties through defect…
The interplay of electronic correlations, spin-orbit coupling and topology holds promise for the realization of exotic states of quantum matter. Models of strongly interacting electrons on honeycomb lattices have revealed rich phase…
The first-order transition at $T_{\rm 0} = 270$ K for the platinum-based SrPt$_2$Sb$_2$ superconductor was investigated using X-ray diffraction and magnetic susceptibility measurements. When polycrystalline SrPt$_2$Sb$_2$ was cooled down…
Spontaneously broken symmetry in the ground state of Bi-based topological materials can lead to promising Topological superconductors, such as Cu-Bi2Se3, Sr-Bi2Se3 and Nb-Bi2Se3. In recent studies, coexistence of multiple Fermi surface…
Two-dimensional van der Waals materials have become an established platform to engineer flat bands which can lead to strongly-correlated emergent phenomena. In particular, the family of Ta dichalcogenides in the 1\textit{T} phase presents a…