Breakdown of weak-field magnetotransport at a metallic quantum critical point.
Breakdown of weak-field magnetotransport at a metallic quantum critical point.
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DOI：
10.1103/physrevlett.95.247201
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发表时间：
2005-07
影响因子：
8.6
通讯作者：
J. Fenton;A. Schofield
中科院分区：
文献类型：
--
作者：
J. Fenton;A. Schofield
我们展示了量子临界金属中能量尺度的崩溃如何导致物理学超越通常用于计算输运量的弱场极限。对于密度波过渡，我们表明，在临界点的有限磁场的存在下，导致不连续的输运系数的温度趋于零。这些不连续性的起源在于弱场琼斯-齐纳展开的崩溃，该展开以前曾被用来论证磁输运系数在简单量子临界点处是连续的。潜在的散射和磁击穿的存在，圆的不连续性在一个窗口确定的τ δ < 1，其中德尔塔是序参数和τ是准粒子的弹性寿命。
We show how the collapse of an energy scale in a quantum critical metal can lead to physics beyond the weak-field limit usually used to compute transport quantities. For a density-wave transition we show that the presence of a finite magnetic field at the critical point leads to discontinuities in the transport coefficients as temperature tends to zero. The origin of these discontinuities lies in the breakdown of the weak-field Jones-Zener expansion which has previously been used to argue that magnetotransport coefficients are continuous at simple quantum critical points. The presence of potential scattering and magnetic breakdown rounds the discontinuities over a window determined by tauDelta < 1 where Delta is the order parameter and tau is the quasiparticle elastic lifetime.