Broken mirror symmetry tuned topological transport in PbTe/SnTe heterostructures

Abstract

The tunability of topological surface states and controllable opening of the Dirac gap are of great importance to the application of topological materials. In topological crystalline insulators (TCIs), crystal symmetry and topology of electronic bands intertwine to create topological surface states and thus the Dirac gap can be modulated by symmetry breaking structural changes of lattice. By transport measurement on heterostructures composed of p-type topological crystalline insulator SnTe and n-type conventional semiconductor PbTe, here we show a giant linear magnetoresistance (up to 2150% under 14 T at 2 K) induced by the Dirac Fermions at the PbTe/SnTe interface. In contrast, PbTe/SnTe samples grown at elevated temperature exhibit a cubic-to-rhombohedral structural phase transition of SnTe lattice below 100 K and weak antilocalization effect. Such distinctive magneto-resistance behavior is attributed to the broken mirror symmetry and gapping of topological surface states. Our work provides a promising application for future magneto-electronics and spintronics based on TCI heterostructures.

Role of topological surface states and mirror symmetry in topological crystalline insulator SnTe as an efficient electrocatalyst

“…For example, the lattice distortion and mirror symmetry breaking induced Dirac gap opening in TCI Pb1-xSnxSe was revealed by scanning tunneling microscopy (29,30) and angle-resolved photoemission spectroscopy (31,32), which is consistent with theoretical calculations (33). Wei et al reported that the broken mirror symmetry due to the cubicrhombohedral structural phase transition can tune topological transport in PbTe/SnTe heterostructures (34). DFT calculations carried out by Dagdeviren et al show that local symmetry breaking obstructs the TSSs of stepped (103) surface of SnTe by a threefold reduction of its spectral weight as compared with the ideal (001) surface (35).…”

Ferromagnetic phase transition in topological crystalline insulator thin films: Interplay of anomalous Hall angle and magnetic anisotropy

“…On the other hand, in the case of the H orientation, the upward cusp is broadened, pointing at a weakening of the contribution from the 2D massless DFs [9,10,46,50,78]. The (111) surface of SnTe is protected by both M and T symmetries.…”

“…with ∆ the energy gap at the Dirac cone and E F the Fermi level. Since the TSS residing at the (111) surface of the SnTe are gapless, then A b = π [46,76,77] and the accumulation of a π Berry phase leads to the observed WAL. However, by applying an external field µ 0 H, the destructive interference of the two time reversed paths brings about a negative ∆σ, as evidenced in Fig.…”

“…The IV-VI compounds have been widely studied as thermoelectric materials, as photodetectors and as dilute magnetic semiconductors [41][42][43][44][45]. The interest in the topological behavior of undoped and magnetically doped IV-VI compounds, both in the bulk and thin layer arrangement, has significantly increased recently [39,40,[43][44][45][46][48][49][50]. By means of ARPES, it was demonstrated, that the four Dirac cones of the TCIs are spin non-degenerate and helically spin-polarized [9,10,38].…”

Non-Trivial Transport Interface in a Hybrid Topological Material With Hexagonal Lattice Arrangement

“…The topologically protected edge state has excellent characteristics of robustness, back-scattering suppression and defect immunity [36][37][38][39][40], which have potential applications for manufacturing new computer chips and other components in the future. In addition, topological insulators can also have been widely applied to the fields of transport in photonic crystals [41], phonon crystals [42] and even circuits composed of classical electronic components [43].…”