Magnetoconductance oscillations in topological crystalline insulator Pb_1-xSn_xTe nanowires

SnTe is a topological crystalline insulator (TCI) with gapless topological states at the surface. However, electrically probing these states is a challenge due to the large charge carrier density in the bulk, which dominates the signal. Therefore, we use the ternary alloy Pb_1-xSn_xTe, for which x can be varied to reduce the carrier density but at the same time undergoes a topological to trivial phase transition for x ≈ 0.35. Here, we report magnetoconductance measurements on Pb_1-xSn_xTe nanowire devices with x = 0.4. We observe periodic oscillations of the magnetoconductance as a function of in-plane magnetic field. The Fourier spectrum after subtracting the background shows three distinct sets of peaks, corresponding to flux values of h/e, h/2e and h/3e. This indicates the Aharonov-Bohm (AB) effect with higher harmonics and the Altschuler-Aronov-Spivak (AAS) effect, which have previously been reported for topological insulator (TI) nanowires. The magnitude of the oscillations is on the order of conductance quantum 2e²/h at mK, and decays exponentially with increasing temperature. These results indicate that Pb_1-xSn_xTe nanowires are a promising platform for electrically probing the topological states in a TCI in quantum transport experiments.