Ma Xixiao, Lan Yu, Qin Ling, Kuang Lülin, Feng Shiping
Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China.
J Phys Condens Matter. 2016 Aug 24;28(33):335601. doi: 10.1088/0953-8984/28/33/335601. Epub 2016 Jun 28.
The notion of the electron Fermi surface is one of the characteristic concepts in the field of condensed matter physics, and it plays a crucial role in the understanding of the physical properties of doped Mott insulators. Based on the t-J model, we study the nature of the electron Fermi surface in the cobaltates, and qualitatively reproduce the essential feature of the evolution of the electron Fermi surface with doping. It is shown that the underlying hexagonal electron Fermi surface obeys Luttinger's theorem. The theory also predicts a Fermi-arc phenomenon at the low-doped regime, where the region of the hexagonal electron Fermi surface along the [Formula: see text]-K direction is suppressed by the electron self-energy, and then six disconnected Fermi arcs located at the region of the hexagonal electron Fermi surface along the [Formula: see text]-M direction emerge. However, this Fermi-arc phenomenon at the low-doped regime weakens with the increase of doping.
电子费米面的概念是凝聚态物理领域的特征性概念之一，它在理解掺杂莫特绝缘体的物理性质方面起着关键作用。基于t-J模型，我们研究了钴酸盐中电子费米面的性质，并定性地再现了电子费米面随掺杂演化的基本特征。结果表明，潜在的六角形电子费米面遵循卢廷格定理。该理论还预测了低掺杂区域的费米弧现象，其中六角形电子费米面沿[公式：见正文]-K方向的区域被电子自能抑制，然后在六角形电子费米面沿[公式：见正文]-M方向的区域出现六个不相连的费米弧。然而，低掺杂区域的这种费米弧现象会随着掺杂量的增加而减弱。
