Shi Zhenzhong, Baity P G, Terzic J, Sasagawa T, Popović Dragana
National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA.
Department of Physics, Duke University, Durham, NC, 27708, USA.
Nat Commun. 2020 Jul 3;11(1):3323. doi: 10.1038/s41467-020-17138-z.
In underdoped cuprates, the interplay of the pseudogap, superconductivity, and charge and spin ordering can give rise to exotic quantum states, including the pair density wave (PDW), in which the superconducting (SC) order parameter is oscillatory in space. However, the evidence for a PDW state remains inconclusive and its broader relevance to cuprate physics is an open question. To test the interlayer frustration, the crucial component of the PDW picture, we perform transport measurements on charge- and spin-stripe-ordered LaEuSrCuO and LaNdSrCuO in perpendicular magnetic fields (H), and also with an additional field applied parallel to CuO layers (H). We detect several phenomena predicted to arise from the existence of a PDW, including an enhancement of interlayer SC phase coherence with increasing H. These data also provide much-needed transport signatures of the PDW in the regime where superconductivity is destroyed by quantum phase fluctuations.
在欠掺杂铜酸盐中，赝能隙、超导性以及电荷和自旋序之间的相互作用会产生奇异的量子态，包括对密度波（PDW），其中超导（SC）序参量在空间中呈振荡分布。然而，PDW态的证据仍然不确凿，其与铜酸盐物理更广泛的相关性仍是一个悬而未决的问题。为了检验层间失配（PDW图景的关键组成部分），我们对电荷和自旋条纹有序的LaEuSrCuO和LaNdSrCuO在垂直磁场（H）以及平行于CuO层施加附加磁场（H）的情况下进行了输运测量。我们检测到了一些预计由PDW的存在而产生的现象，包括随着H增加层间SC相位相干性增强。这些数据还在超导被量子相位涨落破坏的区域提供了急需的PDW输运特征。
