Visualizing the unusual spectral weight transfer in DyBa2Cu3O7-δ thin film

Hui Li; Zengyi Du; Ze-Bin Wu; Daniel Putzky; Sang Hyun Joo; Asish K Kundu; Xiaotao Xu; Xiaoyan Shi; Jinho Lee; Abhay N Pasupathy; Gennady Logvenov; Bernhard Keimer; Tonica Valla; Ivan Božović; Ilya K Drozdov; Kazuhiro Fujita

doi:10.1038/s41598-021-04692-9

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

Sci Rep. 2022 Jan 17;12(1):830. doi: 10.1038/s41598-021-04692-9.

Authors

Hui Li^{1

2}, Zengyi Du¹, Ze-Bin Wu¹, Daniel Putzky³, Sang Hyun Joo⁴, Asish K Kundu¹, Xiaotao Xu^{1

5}, Xiaoyan Shi⁵, Jinho Lee⁴, Abhay N Pasupathy^{1

6}, Gennady Logvenov³, Bernhard Keimer³, Tonica Valla¹, Ivan Božović^{1

7}, Ilya K Drozdov¹, Kazuhiro Fujita⁸

Affiliations

¹ Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
² Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794, USA.
³ Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
⁴ Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea.
⁵ Department of Physics, The University of Texas at Dallas, Richardson, TX, 75080, USA.
⁶ Department of Physics, Columbia University, New York, NY, 10027, USA.
⁷ Department of Chemistry, Yale University, New Haven, CT, 06520, USA.
⁸ Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA. kkfujit@gmail.com.

Abstract

We report a Spectroscopic Imaging Scanning Tunneling Microscopy (SI-STM) study of a DyBa₂Cu₃O_7-δ (DBCO) thin film (T_c ~ 79 K) synthesized by the molecular beam epitaxy (MBE). We observed an unusual transfer of spectral weight in the local density of states (LDOS) spectra occurring only within the superconducting gap. By a systematic control of the tip-sample distance and the junction resistance, we demonstrate that the spectral weight transfer can be switched at a nano-meter length scale. These results suggest that an interaction between the STM tip and the sample alters the electronic configurations in the film. This probably originates from a combination of an intrinsic band bending at the interface between the surface and the bulk, and a tip-induced band bending. These results may open a new avenue for band engineering and applications of thin films of high-T_c cuprates.

Abstract

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