Delocalization of topological surface states by diagonal disorder in nodal loop semimetals

The effect of Anderson diagonal disorder on the topological surface (“drumhead”) states of a Weyl nodal loop semimetal is addressed. Since diagonal disorder breaks chiral symmetry, a winding number cannot be defined. Seen as a perturbation, the weak random potential mixes the clean exponentially localized drumhead states of the semimetal, thereby producing two effects: (i) the algebraic decay of the surface states into the bulk; (ii) a broadening of the low energy density of surface states of the open system due to degeneracy lifting. This behavior persists with increasing disorder, up to the bulk semimetal-to-metal transition at the critical disorder W c . Above W c , the surface states hybridize with bulk states and become extended into the bulk.

[1]  P. Sacramento,et al.  Topology in Condensed Matter , 2021 .

[2]  L. Covaci,et al.  KITE: high-performance accurate modelling of electronic structure and response functions of large molecules, disordered crystals and heterostructures , 2019, Royal Society Open Science.

[3]  M. Ezawa.  Second-order topological insulators and loop-nodal semimetals in Transition Metal Dichalcogenides XTe2 (X = Mo, W) , 2018, Scientific Reports.

[4]  BaoKai Wang,et al.  Experimental observation of drumhead surface states in SrAs3 , 2018, Scientific Reports.

[5]  H. Ding,et al.  Experimental observation of bulk nodal lines and electronic surface states in ZrB2 , 2018, npj Quantum Materials.

[6]  S. Rachel.  Interacting topological insulators: a review , 2018, Reports on progress in physics. Physical Society.

[7]  Benedikt Ernst,et al.  A three-dimensional magnetic topological phase , 2017, 1712.09992.

[8]  Su-Yang Xu,et al.  Topological nodal-line fermions in spin-orbit metal PbTaSe2 , 2016, Nature Communications.

[9]  B. Lotsch,et al.  Dirac cone protected by non-symmorphic symmetry and three-dimensional Dirac line node in ZrSiS , 2015, Nature Communications.

[10]  David Abend,et al.  The Kondo Problem To Heavy Fermions , 2016 .

[11]  Michelle Becker,et al.  Green S Functions For Solid State Physicists , 2016 .

[12]  Shengbai Zhang,et al.  Nanostructured Carbon Allotropes with Weyl-like Loops and Points. , 2015, Nano letters.

[13]  Lilia S. Xie,et al.  A new form of Ca3P2 with a ring of Dirac nodes , 2015 .

[14]  M. Springford.  The Kondo problem to heavy fermions , 1993 .

[15]  D. Vanderbilt.  Berry Phases in Electronic Structure Theory , 2018 .