单层和多层黑磷中的等离激元和屏蔽效应

Plasmons and screening in monolayer and multilayer black phosphorus.

作者信息

Low Tony, Roldán Rafael, Wang Han, Xia Fengnian, Avouris Phaedon, Moreno Luis Martín, Guinea Francisco

机构信息

IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598, USA and Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511, USA and Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.

Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.

出版信息

Phys Rev Lett. 2014 Sep 5;113(10):106802. doi: 10.1103/PhysRevLett.113.106802. Epub 2014 Sep 4.

DOI:10.1103/PhysRevLett.113.106802

PMID:25238376

Abstract

Black phosphorus exhibits a high degree of band anisotropy. However, we find that its in-plane static screening remains relatively isotropic for momenta relevant to elastic long-range scattering processes. On the other hand, the collective electronic excitations in the system exhibit a strong anisotropy. Band nonparabolicity, due to interband couplings, leads to a plasmon frequency which scales as nβ, where n is the carrier concentration, and β<1/2. Screening and charge distribution in the out-of-plane direction are also studied using a nonlinear Thomas-Fermi model.

摘要

黑磷表现出高度的能带各向异性。然而，我们发现，对于与弹性长程散射过程相关的动量，其面内静态屏蔽仍相对各向同性。另一方面，该系统中的集体电子激发表现出很强的各向异性。由于带间耦合导致的能带非抛物线性质，使得等离子体频率按nβ标度，其中n是载流子浓度，且β<1/2。还使用非线性托马斯 - 费米模型研究了面外方向的屏蔽和电荷分布。