SOS: 对称操作相似原理

凝聚态物理学往往为对称性所支配。自发对称性破缺将导致相变，而且许多可观测量或物 理现象都与破缺的对称性有关，如铁电极化、铁磁磁化、旋光性（包括法拉第旋转和磁光克尔旋 转）、二次谐波发生、光伏效应、非互易性、霍尔效应型输运以及多铁性。在这里，我们提出以 下观点：从对称性破缺的角度来看，当构成量（如自旋排列、晶格畸变，或处于外场以及其他环 境中等）或测量方式（如光学探测，或处于不同极性态中电子和其它粒子探测，或对体极化磁 化] 等的测量）遵循对称操作相似(symmetry operational similarity, SOS) 原理时，我们便可以 观测到某些特定的物理现象。这种SOS原理提供了一种在复杂材料中用简洁而清晰的物理图像描 述非直观物理现象的途径。反之，也可以用于甄别具有潜在需求特性的新材料，或发现已知材料 中新的物理现象。

SOS:symmetry-operational similarity

Symmetry often governs condensed matter physics.The action of breaking symmetry spontaneously leads to phase transitions,and various observables or observable physical phenomena can be directly associated with broken symmetries.Examples include ferroelectric polarization,ferromagnetic magnetization,optical activities(including Faraday and magneto-optic Kerr rotations),second harmonic generation,photogalvanic effects,nonreciprocity,various Hall-effect-type transport properties,and multiferroicity.Herein,we propose that observable physical phenomena can occur when specimen constituents(i.e.,lattice distortions or spin arrangements,in external fields or other environments,etc.)and measuring probes/quantities(i.e.,propagating light,electrons or other particles in various polarization states,including vortex beams of light and electrons,bulk polarization or magnetization,etc.)share symmetry operational similarity(SOS)in relation to broken symmetries.The power of the SOS approach lies in providing simple and physically transparent views of otherwise unintuitive phenomena in complex materials.In turn,this approach can be leveraged to identify new materials that exhibit potentially desired properties as well as new phenomena in known materials.