Observation of nodal line in non-symmorphic topological semimetal InBi

Abstract

Topological nodal semimetal (TNS), characterized by its touching conduction and valence bands, is a newly discovered state of quantum matter which exhibits various exotic physical phenomena. Recently, a new type of TNS called topological nodal line semimetal (TNLS) is predicted where its conduction and valence band form a degenerate one-dimension line which is further protected by its crystal symmetry. In this work, we systematically investigated the bulk and surface electronic structure of the non-symmorphic, TNLS in InBi (which is also a type II Dirac semimetal) with strong spin-orbit coupling by using angle resolved photoemission spectroscopy. By tracking the crossing points of the bulk bands at the Brillouin zone boundary, we discovered the nodal-line feature along the k z direction, in agreement with the ab initio calculations and confirmed it to be a new compound in the TNLS family. Our discovery provides a new material platform for the study of these exotic topological quantum phases and paves the way for possible future applications.

Strong spin-orbit coupling and Dirac nodal lines in the three-dimensional electronic structure of metallic rutile IrO2

“…However, the DNLs usu-ally reside far away from E F . For example, similar DNLs have been observed by ARPES in ZrSiS [33,34] and InBi [35], which are hundreds of meV away from the Fermi level. In contrast, the DNLs in IrO 2 cross the Fermi level, which provides an ideal platform to realize a possible application of DNLs.…”

New type of hybrid nodal line semimetal in Be2Si

“…However, such separation between the topological states and Fermi level is not a hinder to detection in experiments. For example, the topological states of nonsymmorphic topological semimetal InBi [29], NLSM ZrSiS [30] and Dirac nodal links materials TiB 2 [74] depart from the Fermi level larger than 0.5eV could be well resolved by ARPES through tuning the photon energy. Moreover, electric gating can routinely tune the Fermi level of the 2D systems with electron or hole doping.…”

“…In comparison with topological insulators [1,2], topological semimetals have gapless bulk states and topologically protected surface states. Up to now, the well-known topological semimetals include Dirac semimetals (DSMs) [3][4][5][6][7][8][9][10], Weyl semimetals (WSMs) [11][12][13][14][15][16][17][18][19][20][21], and node-line semimetals (NLSMs) [22][23][24][25][26][27][28][29][30]. For DSMs and WSMs, their nontrivial band crossing points distribute at separate k points in the Brillouin zone (BZ).…”

“…So far, three types of symmetry protected mechanisms for NLSMs have been proposed: (i) mirror reflection symmetry protected NSLMs [39,40]; (ii) NLSMs derives from combined protection of time reversal symmetry and space inversion symmetry [22,23,[41][42][43][44][45][46]; (iii) NLSMs determined by non-symmorphic space group with glide plane or screw axes symmetries [27,47]. Although many different crystalline symmetries can stabilize the NLSMs, few materials including pure Be [46], PbTaSe 2 [48], ZrSiS [30], PtSn 4 [49], InBi [29], and ZrSiSe/ZrSiTe [50] were experimentally verified as topological NLSMs by angle-resolved photoemission spectroscopy (ARPES). There are challenges to experimental realization and observation of NLSMs.…”

Quantum transport in topological semimetals under magnetic fields (II)

“…The nodal lines are predicted in many materials, such as HgCr 2 Se 4 [20], graphene networks [76], Cu 3 (Pd/Zn)N [77,78], SrIrO 3 [79,80], TlTaSe 2 [81], Ca 3 P 2 [82,83], CaTe [84], compressed black phosphorus [85], CaAg(P/As) [86], CaP 3 family [87], PdS monolayer [88], Zintl compounds [89], BaMX 3 (M=V, Nb and Ta, X=S, Se) [90], rare earth monopnictides [91], alkalineearth compounds [92][93][94], other carbon-based materials [69,95], and metallic rutile oxides XO 2 (X=Ir, Os, Rd) [96]. So far, the nodal lines have been verified in ZrSiS [97][98][99], PbTaSe 2 [100,101], InBi [102] and PtSn 4 [103] by ARPES.…”