Cusnse Materials Exhibit Switching of Topological Phase Transition to Ideal Weyl States Via Bandgap Closure
Summarize this article with:
The search for novel topological phases of matter represents a major frontier in materials science, and researchers continually seek ways to engineer these states with greater control and flexibility. Huan Li, alongside colleagues, demonstrates a groundbreaking pathway to achieve a topological phase transition, moving from a semiconductor to an ideal Weyl semimetal, without relying on conventional methods that require breaking fundamental symmetries. This work reveals that carefully tuning the chemical composition of materials within the Cu SnSe family induces a transition driven by bandgap closure and enhanced spin-orbit coupling, effectively inverting the electronic bands and creating pairs of Weyl points very close to the material’s Fermi level. The resulting material exhibits a unique electronic structure, characterised by point-like bulk Fermi surfaces and exclusively surface Fermi arcs, offering a new and versatile platform for exploring the unusual transport properties inherent to Weyl semimetals and circumventing the limitations of existing symmetry-based engineering approaches. This work investigates how the Cu2SnSe3 family of materials undergoes a topological phase transition, moving from a semiconducting state to one hosting ideal Weyl states, and focuses on how external factors influence this change. Researchers employed sophisticated computational methods to systematically examine the evolution of the material’s electronic band structure and key topological characteristics, specifically investigating how strain or doping alters the band gap, Dirac point positions, and Fermi arc formation. The results demonstrate a clear pathway for inducing a topological phase transition through controlled manipulation of the material’s electronic structure, achieving a transition from a semiconducting state to one hosting ideal Weyl fermions, and providing a fundamental understanding of the underlying mechanisms governing these transitions. A central theme in quantum materials research concerns transitions between Weyl semimetals and other topological states. Conventional approaches rely on disrupting time-reversal symmetry or precisely manipulating the material’s lattice structure, which limits control strategies. This work proposes a novel mechanism for topological phase transition that operates without breaking time-reversal symmetry or modifying the lattice structure, demonstrating that certain semiconductors can be directly transformed into an ideal Weyl semimetal through bandgap closure driven by chemical doping, simultaneously modulating the band gap and enhancing spin-orbit coupling, leading to band inversion.
Doping Induces Topological Phase Transition in Cu2SnSe3 This research demonstrates a novel mechanism for transitioning materials between semiconducting and Weyl semimetal phases, bypassing conventional requirements for symmetry breaking or structural modification.
Scientists have shown that chemical doping can directly induce this topological phase transition by simultaneously modulating the band gap and enhancing spin-orbit coupling within specific materials. Through detailed calculations, the team successfully demonstrated this process in the Cu₂SnSe₃ family of materials, revealing the emergence of Weyl points very close to the material’s Fermi level and the formation of characteristic Fermi arcs on the surface. This achievement offers a new pathway for designing topological materials, as the transition relies solely on compositional tuning and preserves crystal symmetry, offering both experimental feasibility and precise control. The researchers identified Cu₂SnSe₃ and Cu₂GeSe₃ as prototypical Weyl semimetals, exhibiting nearly point-like bulk Fermi surfaces and well-defined surface states. Furthermore, they showed that doping with elements like germanium or tellurium can effectively drive the transition from a semiconductor to a Weyl semimetal phase. While precise classification of these materials requires more accurate lattice parameters and higher-resolution simulations, alongside direct experimental verification of the Fermi surface and surface states, this work establishes a promising strategy for creating ideal Weyl semimetals and offers a valuable route toward realizing Weyl systems with larger separations between Weyl points. Further research into related compounds, such as Cu₂SnS₃, could reveal transitions to different topological phases, like topological insulators, though these systems exhibit more complex surface structures. 👉 More information🗞 Switching of topological phase transition from semiconductor to ideal Weyl states in Cu SnSe family of materials🧠 ArXiv: https://arxiv.org/abs/2512.10201 Tags: Rohail T. As a quantum scientist exploring the frontiers of physics and technology. My work focuses on uncovering how quantum mechanics, computing, and emerging technologies are transforming our understanding of reality. I share research-driven insights that make complex ideas in quantum science clear, engaging, and relevant to the modern world. Latest Posts by Rohail T.: Topology-guided Quantum GANs Generate Constrained K4 Graphs, Enhancing Performance with Geometric Priors December 13, 2025 Nonlocal MOND Model Interpolates Between Cosmology and Gravitationally Bound Systems, Reproducing Dark Matter Phenomena December 13, 2025 Energy Correlator Conformal Blocks Demonstrate Positivity in Field Theory Operator Product Expansions December 13, 2025