AI 中文总结
本研究发现，强破坏反演对称性可使两带非中心对称超导环的带间相位孤子成为基态，其手性由外加磁场设定，平衡态电流-通量测量中可观测到磁场奇宇称的孤子分支。
AI 中文摘要
两带超导体维持着相对带间相位，该相位可在超导环中承载缠绕孤子激发，由两带的独立缠绕数支撑。在具有中心反演对称性的超导体环中，带间相位孤子是亚稳态，其与均匀基态被屏蔽电流的能量分隔。本研究发现，当反演对称性被足够强地破坏时，可使孤子成为真正的基态。此时，中心对称材料中不存在的磁电耦合会在某一阈值以上起关键作用，这一相关自由能项对缠绕数为奇，会偏向特定缠绕符号的能量平衡。一旦该偏向超过原本使孤子成为亚稳态的能量代价，具有有限缠绕数的相位孤子将成为基态，其手性由外加磁场设定。在平衡态下进行的电流-通量测量中，该效应表现为磁场奇宇称的孤子分支，取代了介观环中存在的亚稳态分支，这些介观环由两分量超导体构成，实现了带间相对相位领域中Little-Parks通量oid分支物理的磁电类似物。
英文摘要
Two-band superconductors maintain a relative interband phase which can carry winding soliton excitations in a superconducting ring, supported by independent winding numbers in the two bands. In rings of superconductors obeying the inversion symmetry the interband phase solitons are metastable states, separated from the uniform ground state by the energy of screening currents. In this work we find that, breaking the inversion symmetry strongly enough, one can make the soliton a true ground state. In that case, a magneto-electric coupling, absent in centrosymmetric materials, contributes critically above a certain threshold, a relevant, free-energy term, odd with respect to the winding number, which biases the energy balance in favor of a particular winding sign. Once the bias outweighs the energy cost that originally made the soliton metastable, a phase soliton with a finite winding number becomes the ground state, with chirality set by the applied field. In current--flux measurements performed in equilibrium states, the effect is demonstrated by field-odd soliton branches, that replace the metastable ones existing in mesoscopic rings, built by two-component superconductors, realizing a magneto-electric analog of the Little--Parks fluxoid-branch physics in the interband relative-phase sector.
Comments6 pages of the main text with 4 figures and the supplemental material. Comments are welcome
