Quasiparticle resonant states induced by a unitary impurity in a d-wave superconductor
نویسندگان
چکیده
The quasiparticle resonant states around a single nonmagnetic impurity with unitary scattering in a d-wave superconductor is studied by solving the Bogoliubov–de Gennes equations based on a t-J model. Both the spatial variation of the order parameter and the local density of states ~LDOS! around the impurity have been investigated. We find that ~i! a particle-hole symmetric system has a single symmetric zero-energy peak in the LDOS regardless of the size of the superconducting coherence length j0; ~ii! for the particle-hole asymmetric case, an asymmetric splitting of the zero-energy peak is intrinsic to a system with a small value of kFj0.
منابع مشابه
Impurities and Conductivity in a D-wave Superconductor
Impurity scattering in the unitary limit produces low energy quasiparticles with anisotropic spectrum in a two-dimensional d-wave superconductor. We describe a new quasi-one-dimensional limit of the quasiparticle scattering, which might occur in a superconductor with short coherence length and with finite impurity potential range. The dc conductivity in a d-wave superconductor is predicted to b...
متن کاملAntiferromagnetic correlations and impurity broadening of NMR linewidths in cuprate superconductors
We study a model of a d-wave superconductor with strong potential scatterers in the presence of antiferromagnetic correlations and apply it to experimental nuclear magnetic resonance NMR results on Zn impurities in the superconducting state of YBa2Cu3O7− . We then focus on the contribution of impurity-induced paramagnetic moments, with Hubbard correlations in the host system accounted for in Ha...
متن کاملDensity of States of a d-wave Superconductor in the Presence of Strong Impurity Scatterers: a Non Perturbative Result
We present a method to compute the density of states induced by N non magnetic impurities in a d-wave superconductor, in the unitary limit of very strong scatering centers. For frequencies very small as compared to the su-perconducting gap (ω ≪ ∆ 0) the additional density of states has the leading divergence δρ(ω) ≃ n i / |2ω| ln 2 |ω/∆ 0 | + (π/2) 2. This result is non per-turbative.
متن کاملInfluence of impurity scattering on tunneling conductance in normal metal – d - wave superconductor junctions
Tunneling conductance spectra between a normal metal / d-wave superconductor junction under the presence of bulk impurities in the superconductor are studied. The quasiclassical theory has been applied to calculate the spatial variation of the pair potential and the effect of impurity scattering has been introduced by t-matrix approximation. The magnitude of a subdominant s-wave component at th...
متن کاملResonant states and order-parameter suppression near pointlike impurities in d-wave superconductors
We examine the role of order-parameter suppression in the development of low-energy peaks ~i.e., resonances! in the tunneling density of states near a nonmagnetic impurity in a d-wave superconductor. Without order-parameter suppression, the zero-energy resonance appears only in the unitary ~i.e., strong impurity! limit. However, suppression makes the resonance appear even when the impurity is m...
متن کامل