Pulsed Field Facility, National High Magnetic Field Laboratory, Los Alamos National Laboratory, Mail Stop E536, Los Alamos, New Mexico 87545, USA.
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Nat Commun. 2016 Jul 22;7:12244. doi: 10.1038/ncomms12244.
The observation of a reconstructed Fermi surface via quantum oscillations in hole-doped cuprates opened a path towards identifying broken symmetry states in the pseudogap regime. However, such an identification has remained inconclusive due to the multi-frequency quantum oscillation spectra and complications accounting for bilayer effects in most studies. We overcome these impediments with high-resolution measurements on the structurally simpler cuprate HgBa2CuO4+δ (Hg1201), which features one CuO2 plane per primitive unit cell. We find only a single oscillatory component with no signatures of magnetic breakdown tunnelling to additional orbits. Therefore, the Fermi surface comprises a single quasi-two-dimensional pocket. Quantitative modelling of these results indicates that a biaxial charge density wave within each CuO2 plane is responsible for the reconstruction and rules out criss-crossed charge stripes between layers as a viable alternative in Hg1201. Lastly, we determine that the characteristic gap between reconstructed pockets is a significant fraction of the pseudogap energy.
通过掺杂空穴的铜氧化物中量子振荡观测到重构费米面，为在赝能隙区识别对称性破缺态开辟了一条道路。然而，由于大多数研究中需要考虑双层效应的多频量子振荡谱和复杂性，这种识别仍然没有定论。我们通过对结构更简单的铜酸盐 HgBa2CuO4+δ (Hg1201) 的高分辨率测量克服了这些障碍，Hg1201 每个原始晶胞中具有一个 CuO2 平面。我们仅发现一个单一的振荡分量，没有迹象表明磁击穿隧道到附加轨道。因此，费米面由单个准二维口袋组成。对这些结果的定量建模表明，每个 CuO2 平面内的双轴电荷密度波是导致重构的原因，并排除了层间交叉电荷条纹作为 Hg1201 中一种可行的替代方案。最后，我们确定了重构口袋之间的特征能隙是赝能隙能量的重要部分。
