PIRSA:22020071

Toward realization of novel superconductivity based on twisted van der Waals Josephson junction in Cuprates

APA

Kim, P. (2022). Toward realization of novel superconductivity based on twisted van der Waals Josephson junction in Cuprates. Perimeter Institute. https://pirsa.org/22020071

MLA

Kim, Philip. Toward realization of novel superconductivity based on twisted van der Waals Josephson junction in Cuprates. Perimeter Institute, Feb. 28, 2022, https://pirsa.org/22020071

BibTex

          @misc{ pirsa_22020071,
            doi = {},
            url = {https://pirsa.org/22020071},
            author = {Kim, Philip},
            keywords = {Condensed Matter},
            language = {en},
            title = {Toward realization of novel superconductivity based on twisted van der Waals Josephson junction in Cuprates},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {feb},
            note = {PIRSA:22020071 see, \url{https://pirsa.org}}
          }
          

Abstract

Twisted interfaces between stacked van der Waals Cuprate crystals enable tunable Josephson coupling, utilizing anisotropic superconducting order parameters. Employing a novel cryogenic assembly technique, we fabricate high-temperature Josephson junctions with an atomically sharp twisted interface between Bi_2Sr_2CaCu_2O_{8+x} crystals. The critical current density J_c sensitively depends on the twist angle. While near 0 degree twist, J_c nearly matches that of intrinsic junctions, it is suppressed almost 2-orders of magnitude but remained finite near 45 degree. J_c also exhibits non-monotonic behavior versus temperature due to competition between two supercurrent contributions from nodal and anti-nodal regions of the Fermi surface. Near 45 degree twist angle, we observe two-period Fraunhofer interference patterns and fractional Shapiro steps at half integer values, a signature of co-tunneling Cooper pairs necessary for high temperature topological superconductivity.

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