Bogoliubov angle and visualization of particle-hole mixture in superconductors

被引：27

作者：

Fujita, K. ^{[1
]}

Grigorenko, Ilya ^{[2
]}

Lee, J. ^{[1
]}

Wang, W. ^{[1
]}

Zhu, Jian Xin ^{[3
]}

Davis, J. C. ^{[1
,4
]}

Eisaki, H. ^{[5
]}

Uchida, S. ^{[6
]}

Balatsky, Alexander V. ^{[7
,8
]}

机构：

[1] Cornell Univ, Dept Phys, LASSP, Ithaca, NY 14853 USA

[2] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Ctr Nonlinear Studies, Theoret Div T 11, Los Alamos, NM 87545 USA

[3] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA

[4] Brookhaven Natl Lab, CMPMS Dept, Upton, NY 11973 USA

[5] AIST, Nanoelect Res Inst, Tsukuba 3058568, Japan

[6] Univ Tokyo, Dept Phys, Tokyo 1130033, Japan

[7] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA

[8] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Los Alamos, NM 87545 USA

来源：

PHYSICAL REVIEW B | 2008年 / 78卷 / 05期

关键词：

D O I：

10.1103/PhysRevB.78.054510

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Superconducting excitations-Bogoliubov quasiparticles-are the quantum-mechanical mixture of negatively charged electron (-e) and positively charged hole (+e). Depending on the applied voltage bias in scanning tunneling microscope (STM), one can sample the particle and hole contents of such a superconducting excitation. Recent STM experiments offer unique insight into the inner workings of the superconducting state of superconductors. We propose an observable quantity for STM studies that is a manifestation of the particle-hole dualism of the quasiparticles. We call it a Bogoliubov angle. This angle measures the relative weight of particle and hole amplitudes in the superconducting (Bogoliubov) quasiparticle. We argue that this quantity can be measured locally by comparing the ratios of tunneling currents at positive and negative biases. This Bogoliubov angle allows one to measure directly the energy and position dependent particle-hole admixtures and therefore visualize robustness of superconducting state locally. It may also allow one to measure the particle-hole admixture of excitations in normal state above critical temperature and thus may be used to measure superconducting correlations in pseudogap state.

引用

页数：13

共 35 条

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