论文标题
电荷密度波和Weyl半准阶段y $ _2 $ ir $ _2 $ o $ _7 $
Charge density wave and Weyl Semimetal phase in Y$_2$Ir$_2$O$_7$
论文作者
论文摘要
由电子相关引起的带拓扑和对称性损坏相的微妙相互作用具有巨大的当代相关性，并有可能提供新颖的物理见解。在这里，我们在t <10 k的大量y $ _2 $ _2 $ _2 $ _7 $ _7 $ _2 $ _2 $ _2 $ _2 $ _7 $及其过渡到较高的温度下向Weyl Semimetal（WSM）阶段的过渡。 CDW相通过A）a）电流诱导的非线性电导率在低温下具有负差分电阻，b）低频在低温下以较大的介电常数为单位的介电弛豫，c）c）在热膨胀系数的温度依赖性方面存在异常。 DC和AC传输测量结果证实了在较高温度下的WSM相，该测量显示低频下的电感响应。更有趣的是，我们表明，通过减小晶体大小，可以消除低温CDW相，从而导致WSM相的恢复。
The subtle interplay of band topology and symmetry broken phase, induced by electron correlations, has immense contemporary relevance and potentially offers novel physical insights. Here, we demonstrate charge density wave (CDW) in bulk Y$_2$Ir$_2$O$_7$ for T < 10 K, and its transition to the Weyl semimetal (WSM) phase at higher temperatures. The CDW phase is evidenced by a) current induced nonlinear conductivity with negative differential resistance at low temperature, b) low frequency Debye like dielectric relaxation at low temperature with a large dielectric constant, and c) an anomaly in the temperature dependence of the thermal expansion coefficient. The WSM phase at higher temperature is confirmed by the DC and AC transport measurements which show an inductive response at low frequencies. More interestingly, we show that by reducing the crystallite size, the low temperature CDW phase can be eliminated leading to the restoration of the WSM phase.
