arXiv subjects

Roy H. Nyberg

Publications and source records attributed to Roy H. Nyberg.

3 recordsLinked to original sources

arXiv2007

Identifying Collective Modes via Impurities in the Cuprate Superconductors

We show that the pinning of collective charge and spin modes by impurities in the cuprate superconductors leads to qualitatively different fingerprints in the local density of states (LDOS). In particular, in a pinned (static) spin droplet, the creation of a resonant impurity state is suppressed, the spin-resolved LDOS exhibits a characteristic spatial pattern, and the LDOS undergoes significant changes with increasing magnetic field. Since all of these fingerprints are absent in a charge droplet, impurities are a new probe for identifying the nature and relative strength of collective modes.

cond-mat.str-el↗

arXiv2004

Molecular Nanostructures on the Surface of a d_(x2-y2)-Superconductor

We study molecular nanostructures on the surface of a d_(x2-y2)-wave superconductor. We show that the interplay between the molecular nanostructure's internal excitation spectrum and quantum interference of the scattered host electrons leads to a series of novel effects in the local density of states. We demonstrate that these effects give insight into both the nature of the superconducting pairing correlations and of the intermolecular interactions.

cond-mat.supr-con↗

arXiv2003

Localized Bosonic Modes in Superconductors

We show that a localized bosonic mode acts as a new type of "defect" in s- and d_{x^2-y^2}-wave superconductors. The mode induces bound or resonance states, whose spectral signature are peaks in the superconductor's density of states (DOS). We study the peaks' shape and energy as a function of temperature and the mode's frequency and lifetime. We identify several characteristic signatures of the localized mode that qualitatively distinguishes its effects from those of magnetic or non-magnetic impurities.

cond-mat.str-el↗