Spatially correlated incommensurate lattice modulations in an atomically thin high-temperature <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Bi</mml:mi><mml:mrow><mml:mn>2.1</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Sr</mml:mi><mml:mrow><mml:mn>1.9</mml:mn></mml:mrow></mml:msub><mml:mi>Ca</mml:mi><mml:msub><mml:mi>Cu</mml:mi><mml:mrow><mml:mn>2.0</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>8</mml:mn><mml:mo>+</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math> superconductor
Nicola Poccia, Shu Yang Frank Zhao, Hyobin Yoo, Xiaojing Huang, Hanfei Yan, Yong S. Chu, Ruidan Zhong, Genda Gu, Claudio Mazzoli, Kenji Watanabe, Takashi Taniguchi, Gaetano Campi, Valerii M. Vinokur, Philip Kim
Abstract
The authors present the first nanoscale imaging of X-ray diffraction in atomically thin superconducting Bi${}_{2.1}$Sr${}_{1.9}$CaCu${}_{2.0}$O${}_{8+\ensuremath{\delta}}$ single crystals, employing the scanning X-ray nanobeam 100 nanometers wide. By simultaneously mapping the lattice and superlattice peaks over the crystal, they find that while the lattice peak position remains constant over the scan area, the superlattices peaks vary in position, reflecting mesoscale inhomogeneities. Remarkably, while the two types of superlattice peaks are correlated in k-space position in the bulk, they become anti-correlated when the crystals become two-unit cells thick. Reducing dimensionality towards atomic limit changes the lattice strain locally allowing raising of the new mesoscopic patterns, which controls charge distribution and material electronic properties.