Interplay of charge density wave states and strain at the surface of CeTe2
Interplay of charge density wave states and strain at the surface of CeTe2
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DOI：
10.1103/physrevb.101.245423
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发表时间：
2019-11
影响因子：
3.7
通讯作者：
Bishnu Sharma;M. Singh;Burhan Ahmed;Boning Yu;P. Walmsley;I. Fisher;M. Boyer
中科院分区：
文献类型：
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作者：
Bishnu Sharma;M. Singh;Burhan Ahmed;Boning Yu;P. Walmsley;I. Fisher;M. Boyer
利用扫描隧道显微镜(STM)研究了稀土碲化物的电荷密度波(CDW)态。我们的扫描隧道显微镜测量出人意料地用$q\ensuremath{\sim}0.28\phantom{\rule{0.16em}{0ex}}{a}^{*}$，检测到了单向CDW，这不同于以前对稀土二碲化物的实验和第一性原理研究，而与相关稀土三碲化物的实验测量结果非常接近。此外，在扩展的亚表面缺陷附近，我们在{{mathm{cete}}_{2}$的表面上发现了空间分离和空间共存的单向CDW。我们量化了这种缺陷引起的纳米尺度的应变及其变化，并建立了局域晶格应变与局域建立的CDW态之间的关联，这表明晶格应变在确定建立的CDW态的特性中起着重要的作用。我们的测量探索了弱束缚二维Te片的基本性质，之前的实验和理论工作已经确定它是驱动稀土二碲化物和三碲化物化合物中大部分基本物理的基本成分。
We use scanning tunneling microscopy (STM) to study charge density wave (CDW) states in the rare-earth ditelluride, ${\mathrm{CeTe}}_{2}$. Our STM measurements surprisingly detect a unidirectional CDW with $q\ensuremath{\sim}0.28\phantom{\rule{0.16em}{0ex}}{a}^{*}$, which differs from previous experimental and first-principles studies of the rare-earth ditellurides, and which is very close to what is found in experimental measurements of the related rare-earth tritellurides. Furthermore, in the vicinity of an extended subsurface defect, we find spatially-separated as well as spatially-coexisting unidirectional CDWs at the surface of ${\mathrm{CeTe}}_{2}$. We quantify the nanoscale strain and its variations induced by this defect, and establish a correlation between local lattice strain and the locally-established CDW states; this suggests that lattice strain plays an important role in determining the specific characteristics of the established CDW state. Our measurements probe the fundamental properties of a weakly-bound two-dimensional Te sheet, which experimental and theoretical work has previously established as the fundamental component driving much of the essential physics in both the rare-earth di- and tritelluride compounds.