AI 中文总结
通过量子相位波动理论，发现扭曲铜酸盐双层中的手性d+id'超导态在大部分相图中被抑制，仅存在于窄转角窗口和极低温，并导致一级相变和亚稳态。
AI 中文摘要
继扭曲铜酸盐双层中手性$d+id'$超导性的理论提出后，时间反演对称性破缺（TRSB）的实验特征仍存在高度争议。这里我们证明量子相位波动从根本上重塑了这一手性态的相图。与常规超导序不同，手性$d+id'$态需要层间相位自由度的长程相干，因此本质上易受相位波动影响。纳入这些波动几乎消除了相图大部分区域的手性相，将其限制在狭窄的转角窗口和极低温度。波动驱动的手性破坏产生向$d$波态的一级相变，导致共存和亚稳态。同时，约瑟夫森相位锁定在TRSB量子临界点处被强烈削弱，该临界点完全位于超导区域内。更广泛地，我们的工作确立了量子相位波动作为低维层状量子材料中TRSB相出现的基本约束。
英文摘要
Following theoretical proposals of chiral $d+id'$ superconductivity in twisted cuprate bilayers, experimental signatures of time-reversal symmetry breaking (TRSB) remain highly controversial. Here we demonstrate that quantum phase fluctuations fundamentally reshape the phase diagram of this proposed chiral state. Unlike regular superconducting orders, the chiral $d+id'$ state requires long-range coherence of an interlayer phase degree of freedom and is therefore intrinsically vulnerable to phase fluctuations. Incorporating these fluctuations nearly eliminates the chiral phase over most parts of the phase diagram, restricting it to a narrow twist-angle window and ultra-low temperatures. Phase fluctuations also strongly weaken Josephson phase locking near a twist angle of $45^\circ$. More broadly, our work establishes quantum phase fluctuations as a fundamental constraint on the emergence of TRSB phases in low-dimensional layered quantum materials.
Comments5 pages, 4 figures
