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With a nontrivial topological band and intrinsic magnetic order, two-dimensional (2D) MnBi 2 Te 4 -family materials exhibit great promise for exploring exotic quantum phenomena and potential applications. However, the synthesis of 2D MnBi 2 Te 4 -family materials via chemical vapor deposition (CVD), which is essential for advancing device applications, still remains a significant challenge since it is difficult to control the reactions among multi-precursors and form pure phases. Here, we report a controllable synthesis of high-quality magnetic topological insulator MnBi 2 Te 4 and MnBi 4 Te 7 multilayers via an evaporation-rate-controlled CVD approach. The multilayers are grown on a mica substrate epitaxially, exhibiting a regular triangle shape. By controlling growth temperatures, the thickness and lateral size of the 2D MnBi 2 Te 4 are well regulated. Furthermore, the magneto-transport measurements clearly reveal multistep spin-flop transitions for both odd- and even-number-layered MnBi 2 Te 4 multilayers. Our study marks a significant stride toward future transformative applications in devices based on high-quality, edge- and thickness-controlled 2D magnetic topological quantum materials.

The noble metal alloy AuSn 4 has recently been identified as an intrinsic surface topological superconductor, promisingly hosting the Majorana zero mode (MZM) for topological quantum computing. However, the atomic visualization of its nontrivial surface states and MZM remains elusive. Here, we report the direct observation of unconventional surface states and vortex zero mode in AuSn 4 by scanning tunneling microscopy/spectroscopy. Unlike the trivial metallic bulk states of Sn-terminated surfaces, the Au-terminated surfaces exhibit pronounced surface states near the Fermi level, arising from unconventional Rashba bands characterized by shared helical spin textures. In the superconducting state, the Sn-terminated surfaces exhibit conventional Caroli-de Gennes-Matricon bound states, while the Au-terminated surfaces display sharp zero-energy core states resembling MZMs in a nonquantum-limit condition. This distinction may result from the dominant contribution of unconventional Rashba bands on the Au-terminated surface. Our results provide a new platform for studying termination-dependent topological surface states and MZM in noble-metal-based superconductors.