标题： 瞬子引起的拓扑半金属中的超对称破缺 显示英文标题

标题： Instanton-Induced Supersymmetry Breaking in Topological Semimetals

摘要： 超对称（SUSY）作为标准模型之外的物理基本对称性，在高能物理以外的多个领域找到了重要的应用。 在这里，我们在广泛的拓扑半金属中系统地引入了展示量子力学中基本超对称性质的超对称量子力学——其中通过超对称势有效地捕获了例如由磁场破坏平移对称性的情况。 我们展示了通过超对称势谷中的瞬子效应引起的动力学超对称破缺是拓扑半金属相能隙打开的基本机制，并且瞬子效应的强度与能隙大小成正比。 这种瞬子机制提供了一个简单的判据来判断是否打开了能隙，而无需进行详细的计算，即：有限的能隙打开当且仅当超对称势具有偶数个零点。 我们的理论带来了之前未预料到的结果：由于动力学超对称破缺，即使微小的磁场也可以在拓扑稳健的狄拉克、外尔和节点线半金属相中打开能隙。 总体而言，揭示的超对称量子力学与非均匀拓扑半金属之间的联系可以阐明之前模糊的现象，为未来的探索提供指导，并开辟研究拓扑半金属的新途径。 显示英文摘要

摘要： Supersymmetry (SUSY) proposed as an elementary symmetry for physics beyond the Standard Model has found important applications in various areas outside high-energy physics. Here, we systematically implement supersymmetric quantum mechanics -- exhibiting fundamental SUSY properties in the simple setting of quantum mechanics -- into a wide range of topological semimetals, where the broken translational symmetry, e.g., by a magnetic field, is effectively captured by a SUSY potential. We show that the dynamical SUSY breaking via the instanton effect over the SUSY potential valleys works as the underlying mechanism for the gap opening of the topological semimetallic phases, and the magnitude of the instanton effect is proportional to the energy gap. This instanton mechanism provides a simple criterion for determining whether the energy gap has been opened, without resorting to detailed calculations, i.e., a finite energy gap is opened if and only if the SUSY potential has an even number of zeros. Our theory leads to previously unexpected results: even an infinitesimal magnetic field can open a gap in topologically robust Dirac, Weyl, and nodal-line semimetallic phases due to the dynamical SUSY breaking. Overall, the revealed connection between SUSY quantum mechanics and non-uniform topological semimetals can elucidate previously ambiguous phenomena, provide guidance for future investigations, and open a new avenue for exploring topological semimetals.