Title: Homogeneous superconducting gap in $\mathrm{Dy}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ synthesized by oxide molecular beam epitaxy

Abstract

Much of what is known about high-temperature cuprate superconductors stems from studies based on two surface analytical tools, angle-resolved photoemission spectroscopy (ARPES) and spectroscopic imaging scanning tunneling microscopy (SI-STM). A question of general interest is whether and when the surface properties probed by ARPES and SI-STM are representative of the intrinsic properties of bulk materials. We find this question is prominent in thin films of a rarely studied cuprate $\mathrm{Dy}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ DBCO). We synthesize DBCO films by oxide molecular beam epitaxy and study them by in situ ARPES and SI-STM. Both ARPES and SI-STM show that the surface DBCO layer is different from the bulk of the film—it is heavily underdoped, while the doping level in the bulk is close to optimal doping evidenced by bulk-sensitive mutual inductance measurements. ARPES shows the typical electronic structure of a heavily underdoped CU O₂ plane and two sets of one-dimensional bands originating from the CuO chains with one of them gapped. SI-STM reveals two different energy scales in the local density of states, with one (at ~ 18 meV ) corresponding to the superconductivity and the other one (at ~ 90 meV ) to the pseudogap. Finally, while the pseudogap shows large variations over the length scale of a few nanometers, the superconducting gap is very homogeneous. This indicates that the pseudogap and superconductivity are of different origins.

Authors:

Wu, Ze-Bin  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-7809-6802"

Putzky, Daniel ^[2]; Kundu, Asish K. ^[1]; Li, Hui ^[3]; Yang, Shize  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-0421-006X"

Du, Zengyi ^[1]; Joo, Sang Hyun ^[4]; Lee, Jinho ^[4]; Zhu, Yimei ^[1]; Logvenov, Gennady ^[2]; Keimer, Bernhard ^[2]; Fujita, Kazuhiro ^[1]; Valla, Tonica  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-3237-9102"

Božović, Ivan  ^[5];

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• Search DOE PAGES for ORCID "0000-0001-6400-7461"

Drozdov, Ilya K.  ^[1]

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• Search DOE PAGES for ORCID "0000-0002-8185-1194"

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+ Show Author Affiliations

1. Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Max Planck Inst. for Solid State Research, Stuttgart (Germany)
3. Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States)
4. Seoul National Univ. (Korea, Republic of)
5. Brookhaven National Lab. (BNL), Upton, NY (United States); Yale Univ., New Haven, CT (United States)

Publication Date:

Thu Dec 03 00:00:00 EST 2020

Research Org.:

Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); German Research Foundation (DFG); European Union (EU); Institute for Basic Science in Korea; Seoul National University; National Research Foundation of Korea (NRF)

OSTI Identifier:

1762756

Report Number(s):

BNL-220903-2021-JAAM
Journal ID: ISSN 2475-9953; TRN: US2205906

Grant/Contract Number:  

SC0012704; AC02-98CH10886; 823717ESTEEM3; IBS-R009-G2

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Materials

Additional Journal Information:

Journal Volume: 4; Journal Issue: 12; Journal ID: ISSN 2475-9953

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY