Visualizing the unusual spectral weight shift in DyBa₂Cu₃O_7-δ thin film

As a member of Rare-earth barium copper oxides (Re-123) high temperature superconductors, DyBa₂Cu₃O_7-δ (DBCO) may help understanding the material specifics in the electronic structures of cuprates, but not many studies have been reported yet. Here we report a spectroscopic imaging scanning tunneling microscopy (SI-STM) study of DyBa₂Cu₃O_7-δ thin film, which is synthesized by oxide molecular beam epitaxy (MBE). A mutual conductance measurement shows that the critical temperature T_c is around 78K. In the SI-STM measurements, we have observed an unusual spectral weight transfer in the local density of states spectra, simultaneously forming multiple ring-like patterns in the local density of states maps. By changing the resistance between tip and sample, we also found that such spectral weight transfer showed a junction resistance dependence. In this talk, we will discuss these unusual phenomena and possible implications.