Missing quasiparticles and the chemical potential puzzle in the doping evolution of the cuprate superconductors
Missing quasiparticles and the chemical potential puzzle in the doping evolution of the cuprate superconductors
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DOI：
10.1103/physrevlett.93.267002
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发表时间：
2004-12-31
影响因子：
8.6
通讯作者：
Shen, ZX
中科院分区：
文献类型：
--
作者：
Shen, KM;Ronning, F;Shen, ZX
用角分辨光电子能谱研究了Ca_（2-x）Na_xCuO_2Cl_2从Mott绝缘体到超导体的演化过程。通过测量费米能级附近的激发以及非键态，我们以前所未有的精度跟踪了电子结构和化学势的掺杂依赖性。我们的工作揭示了标准弱相互作用准粒子场景中的失败，包括绝缘体的宽线形状和Mott间隙内化学势的明显自相矛盾的位移。为了解决这个问题，我们开发了一个模型，其中准粒子在半填充时非常小，并在掺杂时生长，使我们能够统一诸如色散和费米波矢量与化学势等属性。
The evolution of Ca2-xNaxCuO2Cl2 from Mott insulator to superconductor was studied using angle-resolved photoemission spectroscopy. By measuring both the excitations near the Fermi energy as well as nonbonding states, we tracked the doping dependence of the electronic structure and the chemical potential with unprecedented precision. Our work reveals failures in the standard weakly interacting quasiparticle scenario, including the broad line shapes of the insulator and the apparently paradoxical shift of the chemical potential within the Mott gap. To resolve this, we develop a model where the quasiparticle is vanishingly small at half filling and grows upon doping, allowing us to unify properties such as the dispersion and Fermi wave vector with the chemical potential.