Electronic structure of the chiral helimagnet and3d-intercalated transition metal dichalcogenideCr1/3Nb

Nicholas Sirica

¹

,

S.-K. Mo

²

,

Federica Bondino

³

et al.

Abstract

Electronic structure of the chiral helimagnet and 3d -intercalated transition metal dichalcogenide C r1/3Nb S2 The electronic structure of the chiral helimagnet Cr 1/3 NbS 2 has been studied with core level and angle-resolved photoemission spectroscopy (ARPES). Intercalated Cr atoms are found to be effective in donating electrons to the NbS 2 layers but also cause significant modifications of the electronic structure of the host NbS 2 material. In particular, the data provide evidence that a description of the electronic structure of Cr 1/3 NbS 2 on the basis of a simple rigid band picture is untenable. The data also reveal substantial inconsistencies with the predictions of standard density functional theory. The relevance of these results to the attainment of a correct description of the electronic structure of chiral helimagnets, magnetic thin films/multilayers, and transition metal dichalcogenides intercalated with 3d magnetic elements is discussed.

QuasiparticleGWband structures and Fermi surfaces of bulk and monolayerNbS2

“…We are grateful to Professor N. Mannella and the other authors of Ref. 35 for the permission to use their ARPES results for comparison with our data, and we acknowledge fruitful discussions with G. Volonakis and N. Zibouche. This work was supported by the Austrian Sci- E0, (d) QP renormalization factor Z n,k , and (e) QP corrections of monolayer NbS2 for all k points of the coarse Wannier grid as a function of E0 for the free-standing monolayer (squares) and with considered substrate (circles).…”

“…4, we compare the QP band structure with ARPES measurements from Ref. 35. We combined the reported experimental results obtained with horizontally and vertically polarized photons in Fig.…”

“…In addition, as only few GW calculations have been reported for metallic TMDs [34], part of this work is to examine the various convergence parameters of the GW calculation for the bulk and the monolayer system. As the main focus of this work, we compare our calculations with recent angleresolved photoemission spectroscopy (ARPES) measurements on bulk NbS 2 [35]. Furthermore, we assess the effects of the increased spatial confinement when going from bulk to the monolayer, and the role of substrates.…”

The nature of ferromagnetism in the chiral helimagnet Cr1/3NbS2

“…Overview of Electronic Structure-Previous work focusing on how the electronic structure of NbS2 is modified with Cr intercalation for temperatures below the helimagnetic transition temperature ( Fig. 1(b)) is reported by N. Sirica, et al 32 . To summarize these results, Fig.…”

“…The states at  have been shown by polarization dependent ARPES to exhibit predominantly out-of-plane orbital character 32 . Therefore, in contrast to our previous ResPES measurements 32 , whose purpose was to identify non-dispersive Cr states remaining on the surface following sample cleave, the photon polarization used in this report was chosen to emphasize only those bulk states having an out-of-plane character through ensuring a component of the photon polarization to lie perpendicular to the sample plane. In doing so, a direct comparison of ResPES spectra taken with photon energies tuned across the Cr L- (Fig.…”