Mientjes Mathijs G C, Guan Xin, Lueb Pim J H, Verheijen Marcel A, Bakkers Erik P A M
Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands.
Eurofins Materials Science Eindhoven, 5656AE Eindhoven, The Netherlands.
Nanotechnology. 2024 May 23;35(32). doi: 10.1088/1361-6528/ad47c8.
Topological crystalline insulators (TCIs) are interesting for their topological surface states, which hold great promise for scattering-free transport channels and fault-tolerant quantum computing. A promising TCI is SnTe. However, Sn-vacancies form in SnTe, causing a high hole density, hindering topological transport from the surface being measured. This issue could be relieved by using nanowires with a high surface-to-volume ratio. Furthermore, SnTe can be alloyed with Pb reducing the Sn-vacancies while maintaining its topological phase. Here we present the catalyst-free growth of monocrystalline PbSnTe in molecular beam epitaxy. By the addition of a pre-deposition stage before the growth, we have control over the nucleation phase and thereby increase the nanowire yield. This facilitates tuning the nanowire aspect ratio by a factor of four by varying the growth parameters. These results allow us to grow specific morphologies for future transport experiments to probe the topological surface states in a PbSnTe-based platform.
拓扑晶体绝缘体（TCIs）因其拓扑表面态而备受关注，拓扑表面态在无散射输运通道和容错量子计算方面具有巨大潜力。一种很有前景的拓扑晶体绝缘体是碲化锡（SnTe）。然而，碲化锡中会形成锡空位，导致空穴密度很高，从而阻碍了对表面拓扑输运的测量。通过使用具有高表面积与体积比的纳米线，这个问题可以得到缓解。此外，碲化锡可以与铅形成合金，减少锡空位，同时保持其拓扑相。在此，我们展示了在分子束外延中无催化剂生长单晶碲化铅锡（PbSnTe）的方法。通过在生长之前增加一个预沉积阶段，我们能够控制成核阶段，从而提高纳米线的产量。通过改变生长参数，这有助于将纳米线的纵横比调整四倍。这些结果使我们能够生长出特定的形貌，用于未来的输运实验，以探测基于碲化铅锡的平台中的拓扑表面态。
