Surface termination dependent quasiparticle scattering interference and magneto-transport study on ZrSiS

Abstract

Dirac nodal line semimetals represent a new state of quantum matters in which the electronic bands touch to form a closed loop with linear dispersion. Here, we report a combined study on ZrSiS by density functional theory calculation, scanning tunnelling microscope (STM) and magneto-transport measurements. Our STM measurements reveal the spectroscopic signatures of a diamond-shaped Dirac bulk band and a surface band on two types of cleaved surfaces as well as a spin-polarized surface band at G at E∼0.6 eV on S-surface, consistent with our band calculation. Furthermore, we find the surface termination does not affect the surface spectral weight from the Dirac bulk bands but greatly affect the surface bands due to the change in the surface orbital composition. From our magnetotransport measurements, the primary Shubnikov-de-Haas frequency is identified to stem from the hole-type quasi-two-dimensional Fermi surface between Γ and X. The extracted non-orbital magnetoresistance (MR) contribution D(θ, H) yields a nearly H-linear dependence, which is attributed to the intrinsic MR in ZrSiS. Our results demonstrate the unique Dirac line nodes phase and the dominating role of Zr-d orbital on the electronic structure in ZrSiS and the related compounds.

Origin of the butterfly magnetoresistance in a Dirac nodal-line system

“…In Ref. 33, a linear in field component for the MR is observed for ZrSiS. Here, our modified-two-band model includes also a linear µ0H term.…”

Projective quasiparticle interference of a single scatterer to analyze the electronic band structure of ZrSiS

“…The QPI analysis around specified point defects can reveal a selective scattering. For example, in the topological nodal-line materials ZrSiS and ZrSiSe [27][28][29], two different types of point defects are found to selectively scatter electronic states of the floating surface band [30,31] and bulk band, respectively [31][32][33][34][35]. In ZrSiSe, both the surface and bulk bands were observed to be scattered by a single defect [31,32], which has not been detected yet in ZrSiS.…”

Tunable large spin Hall and spin Nernst effects in the Dirac semimetals ZrXY (X=Si,Ge;Y=S,Se,Te)Yen1, Guo2 2020Phys. Rev. BSelf Cite372260View full textAdd to dashboardCite

“…S1-S6 in the SM [42]. These are just the end points of the Dirac line-nodes along the X-R and A-M lines at the zone boundaries [30,43], which are protected by the glide mirror operation, as labeled by the red line in e.g., Fig. 4(a).…”

“…For example, the recent studies on the SHE in the rutile oxide Dirac semimetals [26] and the TaAs Weyl semimetal family [27] showed that the anticrossing of the nodal points and nodal lines in these TSMs could be the sources of Among the Dirac semimetals, the studies of the ZrSiStype compounds have been particularly intense in the past few years. The members of the ZrSiS family share the same space group P 4/nmm (No.129), and they all possess the symmetry protected Dirac nodal features in the band structures [23,[28][29][30]. In addition, several exotic quantum phenomena such as highly anisotropic magnetoresistance [31], gapless Dirac surface states in topological crystalline insulator (TCI) phase [29], Shubnikovde Haas and de Haas-van Alphen oscillations [30,32], have been observed in some compounds of the family.…”

“…The members of the ZrSiS family share the same space group P 4/nmm (No.129), and they all possess the symmetry protected Dirac nodal features in the band structures [23,[28][29][30]. In addition, several exotic quantum phenomena such as highly anisotropic magnetoresistance [31], gapless Dirac surface states in topological crystalline insulator (TCI) phase [29], Shubnikovde Haas and de Haas-van Alphen oscillations [30,32], have been observed in some compounds of the family. Nonetheless, the spin Hall effect and spin Nernst effect in such systems have not been studied yet.…”