Université Bordeaux, LOMA, UMR 5798, F-33400 Talence, France.
Phys Rev Lett. 2013 May 31;110(22):226403. doi: 10.1103/PhysRevLett.110.226403.
We study the low-energy states of Kondo alloys as a function of the magnetic impurity concentration per site x and the conduction electron average site occupation n(c). Using two complementary approaches, the mean-field coherent potential approximation and the strong-coupling limit, we identify and characterize two different Fermi-liquid regimes. We propose that both regimes are separated by a Lifshitz transition at x=n(c). Indeed, we predict a discontinuity of the number of quasiparticles that are enclosed in the Fermi surface. This feature could provide a scenario for the non-Fermi liquid properties that were recently observed in Kondo alloy systems around x=n(c).
我们研究了 Kondo 合金的低能态，作为每个位置的磁杂质浓度 x 和传导电子平均位置占据数 n(c) 的函数。我们使用两种互补的方法，平均场相干位近似和强耦合极限，确定并描述了两种不同的费米液体态。我们提出，这两个态在 x=n(c)处通过 Lifshitz 转变分开。实际上，我们预测了在费米面内包含的准粒子数的不连续性。这一特征可以为最近在 x=n(c)附近的 Kondo 合金系统中观察到的非费米液体性质提供一种情景。
