Evidence for multiband superconductivity and charge density waves in Ni-doped ZrTe2

Superconductivity in Te-Deficient ZrTe2

“…Consistently, SC in ZrTe 2 intercalated with Ni and Cu has also been linked to multiband behavior. 44,45 Given that SC in Te-deficient ZrTe 1.8 is also consistent with multiband behavior, we propose that the multigap SC state often observed in intercalated TMDs is not necessarily related to the intercalation, but rather it is intrinsically related to the TMDs electronic structure.…”

“…The total DOS at the Fermi level for pure ZrTe 2 is 1.1 states/eV. This value is consistent with previous calculations, which include the spin−orbit coupling, 45 yielding 1.0 states/eV at the Fermi level, a percentage difference of only 8% with respect to our results without including spin−orbit coupling. From the 1.1 states/eV, approximately 53% originate from the Zr-d electron pockets, whereas 42% are coming from the Te-p hole pockets.…”

“…The focus of this work is the ZrTe 2– x TMD, a Te-deficient compositional modification of the ZrTe 2 which crystallizes in the well-known CdI 2 -prototype structure P 3̅ m 1 (164), which is attracting intense attention from the physical chemistry research community. − Ionic intercalation can be accomplished in ZrTe 2 , by positioning the foreign species in the van der Waals gap, frequently leading to SC, e.g., Cu x ZrTe 2 ( T c ≈ 9.0 K) and Ni x ZrTe 2 ( T c ≈ 4.0 K). , In the case of Ni x ZrTe 2 , for instance, the possible coexistence of multigap superconductivity and CDW ( T CDW ≈ 287 K) instabilities are well established. Additionally, recent angle-resolved photoemission spectroscopy and de Haas–van Alphen oscillations experiments also suggest that ZrTe 2 can be regarded as a Dirac semimetal with massless 4-fold quasiparticles. , Due to the possible coexistence of SC and nontrivial topological properties, ZrTe 2 is an excellent candidate for probing the interplay between different emergent quantum states.…”

“…While the connection between intercalation and SC has been reported in ZrTe 2 , , the effect of slight compositional variations and defects has not been probed. Here we address the effect of Te deficiency on the electronic properties of ZrTe 2 , and we show that SC can emerge due to slight structural and electronic modifications.…”

Semiconductor–Metal Phase Transition and Emergent Charge Density Waves in 1T-ZrX2 (X = Se, Te) at the Two-Dimensional Limit

“…The defect-mediated local doping and therefore CDW condensation might be the possible causes for it, as well as the robust CDW in 2 TL ZrSe 2 and multilayer ZrTe 2 films . This comes to another prominent concern about how the CDW of ZrX 2 (X = Se, Te) evolves with doping level and interplays with other collective phenomena such as superconductivity observed in alkali-metal intercalated ZrSe 2 and predicted in Ni-doped ZrTe 2 . , In any event, our results reveal a unique compatibility between the simple FS topology and the CDW phase and open new avenues toward creating and controlling the many-body CDW phase in semiconductors. Apparently, dimensionality and interface engineering of TMDCs, including the semiconducting species, may discover more exotic CDW systems and shed important light on the CDW mechanism in the layered materials.…”