Bogoliubov angle and visualization of particle-hole mixture in superconductors

K. Fujita,1 Ilya Grigorenko,2 J. Lee,1 W. Wang,1 Jian Xin Zhu,3 J. C. Davis,1,4 H. Eisaki,5 S. Uchida,6 and Alexander V. Balatsky7 1LASSP, Department of Physics, Cornell University, Ithaca, New York 14853, USA 2Theoretical Division T-11, Center for Nonlinear Studies, Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 3Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 4CMPMS Department, Brookhaven National Laboratory, Upton, New York 11973, USA 5Nanoelectronics Research Institute, AIST, Ibaraki 305-8568, Japan 6Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan 7Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA Received 4 September 2007; revised manuscript received 17 June 2008; published 13 August 2008