Electronic band structure in pristine and Sulfur-doped Ta${}_2$NiSe${}_5$

Abstract

We present an angle-resolved photoemission study of the electronic band structure of the excitonic insulator Ta${}_2$NiSe${}_5$, as well as its evolution upon Sulfur doping. Our experimental data show that while the excitonic insulating phase is still preserved at a Sulfur-doping level of 25$\%$, such phase is heavily suppressed when there is a substantial amount, $\sim$ 50$\%$, of S-doping at liquid nitrogen temperatures. Moreover, our photon energy-dependent measurements reveal a clear three dimensionality of the electronic structure, both in Ta${}_2$NiSe${}_5$ and Ta${}_2$Ni(Se${}_{1-x}$S${}_x$)${}_5$ ($x=0.25,0.50$) compounds. This suggests a reduction of electrical and thermal conductivities, which might make these compounds less suitable for electronic transport applications.

References in corpus (4)

• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
• Hybridization-gap Formation and Superconductivity in the Pressure-induced Semimetallic Phase of the Excitonic Insulator Ta${}_2$NiSe${}_5$
• Detecting photoelectrons from spontaneously formed excitons

Cited by in corpus (1)

• Anomalous excitonic phase diagram in band-gap-tuned Ta2Ni(Se,S)5