QMC COLLOQUIUM: Guang Bian - University of Missouri

Design, Synthesis, and Characterizations of Topological Quantum Materials

With continued advances in the synthesis of high-qualityepitaxial atomic layers and heterostructures, exciting opportunities are emerging to explore novel quantum phenomena in low-dimensional materials. In this talk, I will highlight two recently explored quantum states intwo-dimensional materials. (1) 2D Weyl/half-Dirac semimetal in epitaxial Bimonolayers: We have observed a 2D Weyl/half-Dirac semimetal in epitaxial Bimonolayers [1]. The spin-polarized massless bulk bands and topologicalFermi-string edge states provide new insights into the topological properties of relativistic electrons in reduced dimensions [2]. Furthermore, coupling this2D Weyl semimetal to superconductors offers a promising route to realizinghigher-order topological superconductivity, accompanied by the emergence of Majorana corner states [3]. (2) Altermagnetism in magnetically intercalated transition metal dichalcogenides: Altermagnetic materials have recently emerged as a promising platform for exploring unconventional quantum phases, owing to their distinctive spin-split band structures despite having zero net magnetization. We present a first-principles investigation of magnetically intercalated transition metal dichalcogenides with the chemical formula XY₄Z₈[4]. Our results establish magnetically intercalated TMDs as a versatile materials platform for engineering altermagnetism, flat bands, and Weyl fermions within a single family of materials.

References:

[1] Q. Lu et al., Nature Communications 15,6001 (2024)

[2] D. J. P. de Sousa et al., Physical Review Letters 133, 146605 (2024)

[3] C.-K. Chiu et al., arXiv:2412.06150

[4] A. Sah et al., npj Quantum Materials 11,63 (2026)