Within the ideal Fermi liquid picture, the impurity-induced spatial modulation of local density of states (LDOS) in the d-wave superconductor Bi2Sr2CaCu2O8 is investigated at different superconducting (SC) gap sizes. These LDOS spectra are related to the finite-temperature dI/dV spectra in scanning tunneling microscopy (STM), when the Fermi distribution factor is deconvoluted away from dI/dV. We find stripe-like structures even in the zero gap case due to a local-nesting mechanism. This mechanism is different from the octet-scattering mechanism in the d-wave SC (dSC) state proposed by McElroy et al. [K. McElroy, R.W. Simmonds, J.E. Huffman, D.H. Lee, J. Orenstein, H. Eisaki, S. Uchida, J.C. Davis, Nature 422 (2003) 592]. The zero gap LDOS is related to the normal state dI/dV. The zero gap spectra when Fourier-transformed into the reciprocal space, can reveal the information of the entire Fermi surface at a single measuring bias voltage, in contrast to the point-wise tracing out proposed by McElroy et al. This may serve as another way to check the reality of Landau quasiparticles in the normal state. We have also re-visited the octet-scattering mechanism in the dSC state and pointed out that, due to the Umklapp symmetry, there are additional peaks in the reciprocal space that experimentally yet to be found.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering