标题： 非线性二元周期系统中的自发对称破缺 显示英文标题

标题： Spontaneous Symmetry Breaking In Nonlinear Binary Periodic Systems

摘要： 自发对称性破缺（SSB）发生在对称的双势阱势中，由于势的非线性超过临界值，导致出现不对称轮廓的模式。 在本研究中，我们研究了一维和二维周期系统中，单元本身为对称双势阱的周期势中的SSB。 使用紧束缚模型，我们推导出预测一维和二维系统中SSB发生临界功率的解析形式。 结果表明，临界功率显著依赖于布洛赫模式的准动量，随着动量模的增加，SSB阈值迅速下降，可能降至零。 这些解析结果得到了非线性本征模式的数值分析和布洛赫模式直接传播模拟的支持。 显示英文摘要

摘要： Spontaneous symmetry breaking (SSB) occurs when modes of asymmetric profile appear in a symmetric, double-well potential, due to the nonlinearity of the potential exceeding a critical value. In this study, we examine SSB in a periodic potential where the unit cell itself is a symmetric double-well, in both one-dimensional and two-dimensional periodic systems. Using the tight-binding model, we derive the analytical form that predicts the critical power at which SSB occurs for both 1D and 2D systems. The results show that the critical power depends significantly on the quasi-momentum of the Bloch mode, and as the modulus of momentum increases, the SSB threshold decreases rapidly, potentially dropping to zero. These analytical findings are supported by numerical nonlinear eigenmode analysis and direct propagation simulations of Bloch modes.