Huang H, Lee S-J, Ikeda Y, Taniguchi T, Takahama M, Kao C-C, Fujita M, Lee J-S
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan.
Phys Rev Lett. 2021 Apr 23;126(16):167001. doi: 10.1103/PhysRevLett.126.167001.
The presence of a small concentration of in-plane Fe dopants in La_{1.87}Sr_{0.13}Cu_{0.99}Fe_{0.01}O_{4} is known to enhance stripelike spin and charge density wave (SDW and CDW) order and suppress the superconducting T_{c}. Here, we show that it also induces highly two-dimensional superconducting correlations that have been argued to be the signatures of a new form of superconducting order, the so-called pair density wave (PDW) order. In addition, using resonant soft x-ray scattering, we find that the two-dimensional superconducting fluctuation is strongly associated with the CDW stripe. In particular, the PDW signature first appears when the correlation length of the CDW stripe grows over eight times the lattice unit (∼8a). These results provide critical conditions for the formation of the PDW order.
已知在La_{1.87}Sr_{0.13}Cu_{0.99}Fe_{0.01}O_{4}中存在少量面内铁掺杂剂会增强条纹状自旋和电荷密度波（SDW和CDW）序，并抑制超导转变温度T_{c}。在此，我们表明它还会诱导出高度二维的超导关联，这种关联被认为是一种新的超导序形式，即所谓的对密度波（PDW）序的特征。此外，利用共振软X射线散射，我们发现二维超导涨落与CDW条纹密切相关。特别是，当CDW条纹的关联长度增长超过晶格单位的八倍（约8a）时，PDW特征首次出现。这些结果为PDW序的形成提供了关键条件。
