While charge density wave (CDW) instabilities are ubiquitous to superconducting cuprates, the different ordering wave vectors in various cuprate families have hampered a unified description of the CDW formation mechanism. Here, we investigate the temperature dependence of the low-energy phonons in the canonical CDW-ordered cuprate La 1.875 Ba 0.125 CuO 4 . We discover that the phonon softening wave vector associated with CDW correlations becomes temperature dependent in the high-temperature precursor phase and changes from a wave vector of 0.238 reciprocal lattice units (r.l.u.) below the ordering transition temperature to 0.3?r.l.u. at 300?K. This high-temperature behavior shows that “214”-type cuprates can host CDW correlations at a similar wave vector to previously reported CDW correlations in non-214-type cuprates such as YBa 2 Cu 3 O 6 + δ . This indicates that cuprate CDWs may arise from the same underlying instability despite their apparently different low-temperature ordering wave vectors.
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机译：虽然电荷密度波（CDW）不稳定性普遍存在于超导铜酸盐，但各种铜酸盐家族中的不同排序波载体阻碍了CDW形成机制的统一描述。在这里，我们研究了低能量声子在规范CDW订购的铜酸铜铜1.875ba 0.125 CUO 4中的温度依赖性。我们发现与CDW相关相关的声音软化波载体变为高温前体相的温度，并从0.238倒数晶格单元（R.L.u.）的波向量的变化在下降到0.3Ω·r.u以下0.238倒数晶格单元（R.u.u.）的变化。在300？k。该高温行为表明，“214” - 型铜酸铜可以在类似的波向量中宿主CdW相关性，以先前报道的非214型铜酸盐中的CDW相关性，例如YBA 2 Cu 3 O 6 +δ。这表明铜替换CDW可能从相同的潜在的稳定性中出现，尽管它们显然不同的低温排序波矢量。
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