Strain is ubiquitous in solid-state materials, but despite its fundamental importance and technological relevance, leveraging externally applied strain to gain control over material properties still infancy. In particular, the diverse phase transitions topological states two-dimensional (2D) transition metal dichalcogenides (TMDs) remains an open challenge. Here, we exploit uniaxial stabilize long-debated structural ground state of 2D semimetal IrTe$_2$, which hidden unstrained samples....

We address the long-standing problem of ground state 1T-TaS_{2} by computing correlated electronic structure stacked bilayers using GW+EDMFT method. Depending on surface termination, semi-infinite uncorrelated system is either band insulating or exhibits a metallic state. For realistic values on-site and inter-site interactions, Mott gap opens in state, but it smaller than originating from bilayer structure. Our results are consistent with recent scanning tunneling spectroscopy measurements...

Interlayer coupling is strongly implicated in the complex electronic properties of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>1</a:mn><a:mi>T</a:mi></a:mrow><a:mo>−</a:mo><a:msub><a:mi>TaS</a:mi><a:mn>2</a:mn></a:msub></a:math>. Uniaxial strain engineering offers a route to modify this order elucidate its interplay with structure and correlations. Here, we employ angle-resolved photoemission spectroscopy (ARPES) reveal effect uniaxial on <b:math...

The transition-metal dichalcogenide tantalum disulphide ($1\mathit{T}\text{\ensuremath{-}}\mathrm{TaS}{}_{2}$) hosts a commensurate charge density wave (CCDW) at temperatures below 165 K where it also becomes insulating. low temperature CCDW phase can be driven into metastable ``mosaic'' by means of either laser or voltage pulses, which shows large CDW domain walls as well closing the electronic band gap. exact origins this pulse-induced metallic mosaic are not yet fully understood. Here,...

$\alpha$-GeTe(111) is a non-centrosymmetric ferroelectric material, for which strong spin-orbit interaction gives rise to giant Rashba split states in the bulk and at surface. The detailed dispersions of surface inside band gap remains an open question because they are located unoccupied part electronic structure, making them inaccessible static angle-resolved photoemission spectroscopy. We show that this difficulty can be overcome via in-situ potassium doping surface, leading rigid shift 80...

Using angle-resolved photoemission spectroscopy, combined with first principle and coupled self-consistent Poisson-Schr\"odinger calculations, we demonstrate that potassium (K) atoms adsorbed on the low-temperature phase of $1T\text{\ensuremath{-}}{\mathrm{TiSe}}_{2}$ induce creation a two-dimensional electron gas (2DEG) quantum confinement its charge-density wave (CDW) at surface. By further changing K coverage, tune carrier density within 2DEG allows us to nullify, surface, electronic...

In the transition metal dichalcogenide ${\mathrm{IrTe}}_{2}$, low-temperature charge-ordered phase transitions involving Ir dimers lead to occurrence of stripe phases different periodicities, and nearly degenerate energies. Bulk-sensitive measurements have shown that, upon cooling, ${\mathrm{IrTe}}_{2}$ undergoes two such first-order $(5\ifmmode\times\else\texttimes\fi{}1\ifmmode\times\else\texttimes\fi{}5)$ $(8\ifmmode\times\else\texttimes\fi{}1\ifmmode\times\else\texttimes\fi{}8)$...

Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated the intertwined lattice and electronic degrees freedom. Here, we report an inelastic x-ray scattering investigation dynamics canonical CDW compound 2H-TaSe2 complemented by angle-resolved photoemission spectroscopy density functional perturbation theory. Our results rule out formation a central-peak without full phonon softening for transition in provide...

Over the past decades, investigations of anomalous low-energy electronic properties $\mathrm{Zr}{\mathrm{Te}}_{5}$ have reached a wide array conclusions. An open question is growth method's impact on stoichiometry samples, especially given very small density states near its chemical potential. Here we report high-resolution scanning tunneling microscopy and spectroscopy measurements performed samples grown via different methods. Using functional theory calculations, identify most prevalent...

Abstract Electron-phonon coupling, i.e., the scattering of lattice vibrations by electrons and vice versa, is ubiquitous in solids can lead to emergent ground states such as superconductivity charge-density wave order. A broad spectral phonon line shape often interpreted a marker strong electron-phonon coupling associated with Fermi surface nesting, parallel sections connected momentum. Alternatively phonons are known arise from atomic anharmonicity. Here, we show that broadening occur...

Interlayer coupling is strongly implicated in the complex electronic properties of 1$T$-TaS$_2$ , but interplay between this and correlations remains unresolved. Here, we employ angle-resolved photoemission spectroscopy (ARPES) to reveal effect uniaxial strain engineering on structure interlayer . The normally insulating ground state transformed into a correlated-metal phase under strain, as evidenced by emergence narrow band at Fermi level. Temperature dependent ARPES measurements that...

Chemical substitution is commonly used to explore new ground states in materials, yet the role of disorder often overlooked. In Mn-substituted ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$ (MnBFA), superconductivity (SC) absent, despite being observed for nominal hole-doped phases. Instead, a glassy magnetic phase emerges, associated with $S=5/2$ Mn local spins. this work, we present comprehensive investigation electronic structure MnBFA using angle-resolved photoemission spectroscopy (ARPES). We...

For a significant composition range, the suppression of spin density wave transition temperature ( T_{\text{SDW}} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>T</mml:mi><mml:mtext mathvariant="normal">SDW</mml:mtext></mml:msub></mml:math> ) in Cr- and Mn-substituted BaFe _{2} display="inline"><mml:msub><mml:mi/><mml:mn>2</mml:mn></mml:msub></mml:math> As (CrBFA MnBFA, respectively) coincides as function Cr/Mn content, despite distinct electronic...

The semimetallic or semiconducting nature of the transition metal dichalcogenide 1$T$-TiSe$_2$ remains under debate after many decades mainly due to fluctuating its 2 $\times$ charge-density-wave (CDW) phase at room-temperature. In this letter, using angle-resolved photoemission spectroscopy, we unambiguously demonstrate that normal state is with an electron-hole band overlap $\sim$110 meV by probing low-energy electronic states perturbed CDW strongly doped alkali atoms. Our study not only...

Using angle-resolved photoemission spectroscopy, combined with first principle and coupled self-consistent Poisson-Schrödinger calculations, we demonstrate that potassium (K) atoms adsorbed on the low-temperature phase of 1$T$-TiSe$_2$ induce creation a two-dimensional electron gas (2DEG) quantum confinement its charge-density-wave (CDW) at surface. By further changing K coverage, tune carrier-density within 2DEG allows us to nullify, surface, electronic energy gain due exciton condensation...

The transport properties of graphene change strongly in the presence electric fields due to graphene's band structure. This makes sensitive charges an insulator substrate. Graphene on SiO2/Si is studied under x-ray irradiation ambient conditions. Using metal oxide semiconductor structure their samples, authors observe remote doping creation positive by and relate them resistance Hall effect measurements performed gate. observed changes conductivity, charge carrier density, corresponding...

Abstract The transition-metal dichalcogenide tantalum disulphide (1 T -TaS 2 ) hosts a commensurate charge density wave (CCDW) at temperatures below 165 K where it also becomes insulating. low temperature CCDW phase can be driven into metastable "mosaic" by means of either laser or voltage pulses which shows large CDW domain walls as well closing the electronic band gap. exact origins this pulse-induced metallic mosaic are not yet fully understood. Here, we observe occurrence such on surface...

We present a combined angle-resolved photoemission spectroscopy and low-energy electron diffraction (LEED) study of the prominent transition metal dichalcogenide IrTe$_2$ upon potassium (K) deposition on its surface. Pristine undergoes series charge-ordered phase transitions below room temperature that are characterized by formation stripes Ir dimers different periodicities. Supported density functional theory calculations, we first show K atoms dope topmost layer with electrons, therefore...

Chemical substitution is commonly used to explore new ground states in materials, yet the role of disorder often overlooked. In Mn-substituted BaFe$_{2}$As$_{2}$ (MnBFA), superconductivity (SC) absent, despite being observed for nominal hole-doped phases. Instead, a glassy magnetic phase emerges, associated with $S=5/2$ Mn local spins. this work, we present comprehensive investigation electronic structure MnBFA using angle-resolved photoemission spectroscopy (ARPES). We find that causes...

The absence of superconductivity (SC) in Cr-substituted BaFe$_{2}$As$_{2}$ (CrBFA) is a well-established but poorly understood topic. It also established that the suppression spin density wave transition temperature ($T_{\text{SDW}}$) CrBFA and Mn-substituted (MnBFA) almost coincides as function Cr/Mn concentrations, irrespective putative distinct electronic effects these substitutions. In this work, we employ angle-resolved photoemission spectroscopy (ARPES) combined functional theory plus...

Over the past decades, investigations of anomalous low-energy electronic properties ZrTe$_5$ have reached a wide array conclusions. An open question is growth method's impact on stoichiometry samples, especially given very small density states near its chemical potential. Here we report high resolution scanning tunneling microscopy and spectroscopy measurements performed samples grown via different methods. Using functional theory calculations, identify most prevalent types atomic defects...

Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated the intertwined lattice and electronic degrees freedom. Here, we report an inelastic x-ray scattering investigation dynamics canonical CDW compound $2H$-TaSe$_2$ complemented by angle-resolved photoemission spectroscopy. Our results rule out central-peak scenario for transition in provide evidence a novel precursor phase above temperature $T_{CDW}$. The...

The transition-metal dichalcogenide tantalum disulphide (1$T$-TaS$_2$) hosts a commensurate charge density wave (CCDW) at temperatures below 165~K where it also becomes insulating. low temperature CCDW phase can be driven into metastable "mosaic" by means of either laser or voltage pulses which shows large CDW domain walls as well closing the electronic band gap. exact origins this pulse-induced metallic mosaic are not yet fully understood. Here, using scanning tunneling microscopy and...