电荷密度波导体三硒化铌的低温集体输运和动力学
Low-Temperature Collective Transport and Dynamics in Charge Density Wave Conductor Niobium Triselenide
摘要：
我们研究了电荷密度波（CDW）导体NbSe 3中的低温动力学，NbSe 3是一类被广泛研究的具有淬火无序的驱动周期性介质系统的代表，并且与更广泛的一组表现出集体输运行为的系统相关。到目前为止，理论上的努力还没有收敛到产生一个一致的描述，在这些系统中观察到的丰富的动态，特别是在低温制度。我们开发了现代样品制备技术，并使用频率和时域传输测量低于第二特征Peierls CDW转变，以调查制度的时间有序的集体蠕变NbSe 3样品在低温制度之间的15 K和32 K。通过测量两个特征阈值场之间的相干振荡的频率，ET和ET*，我们表明，在9个高质量的样品，纯，Ta-，或Ti掺杂，在这个制度的集体运输的电流场关系密切遵循修改后的安德森-金形式跨越5个数量级的热和场激活行为ET以上的温度范围。这项研究，结合我们的输运弛豫测量，提供了相关的长度，能量和时间尺度，设置在这个政权的动态，并揭示了集体动态，由大的长度和能量尺度，必须与微观局部动力学相协调，在数量级较小的尺度的障碍。集体机制和局部机制之间的相互作用决定了一种动态，这种动态导致了极其缓慢（类似爬行）的集体行为，但又是时间有序的。结合现有的工作，我们的研究结果描绘了一个一致的图片CDW的运输相图，和密度波系统一般，并提供必要的成分，这些系统急需正确的理论描述。
英文摘要：
We investigated low-temperature dynamics in a charge density wave (CDW) conductor NbSe3, a widely studied representative of a class of systems of driven periodic media with quenched disorder and relevant to a wider group of systems exhibiting collective transport behaviors. To date, theoretical efforts have not converged to produce a consistent description of the rich dynamics observed in these systems, especially in the low temperature regime. We developed modern sample preparation techniques and used frequency- and time-domain transport measurements below the second characteristic Peierls CDW transition to investigate the regime of temporally-ordered collective creep in NbSe3 samples in the low temperature regime between 15 K and 32 K. By measuring the frequency of coherent oscillations between two characteristic threshold fields, ET and ET*, we show that in nine high-quality samples, pure, Ta-, or Ti-doped, the current-field relation for the collective transport in this regime closely follows a modified Anderson-Kim form across five orders of magnitude with thermally- and field-activated behavior above ET for a range of temperatures. This study, combined with our transport relaxation measurements, provides relevant length, energy, and time scales that set the dynamics in this regime and reveals that the collective dynamics, governed by large length and energy scales, must be reconciled with microscopic local dynamics, with barriers at orders of magnitude smaller scales. The interplay between the collective and local mechanisms set the dynamics that is responsible for extremely slow (creep-like) collective, yet temporally-ordered behavior. Combined with the existing work, our results paint a consistent picture of a transport phase diagram for CDWs, and density-wave systems in general, and provide essential ingredients for a much-needed correct theoretical description of these systems.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
