Over-100µs tunable planar transmons: epitaxial Josephson Junctions and design optimization*

ORAL

Abstract

Since superconducting qubits discovery over twenty years ago energy relaxation times has been improved by several orders. Josephson junctions, a crucial nonlinear component of superconducting qubits, are still fabricated from two aluminum polycrystalline electrodes with lossy amorphous aluminum oxide in between. Here we demonstrate our results in reducing two-level states (TLS) in amorphous oxides by means of Josephson Junctions optimization, thus reducing the participation of the lossy materials and interfaces. We carry out a comparative analysis of tunable X-mon qubit lifetimes based on various Josephson Junctions design types, demonstrating several times coherence improvement. From the other hand, we propose novel superconducting qubits fabrication technique based on Josephson junction epitaxial growth with inorganic masks. To experimentally test the proposed approaches we demonstrate tunable X-mon qubits with coherence over 100 microseconds.

*Devices were fabricated at the BMSTU Nanofabrication Facility (Functional Micro/Nanosystems, FMNS REC, ID 74300).

–

Presenters

  • Aleksei Matanin

    • FMN Laboratory, Bauman Moscow State Technical University

Authors

  • Anastasiya Pishchimova

    • FMN Laboratory, Bauman Moscow State Technical University

  • Dmitriy Moskalev

    • FMN Laboratory, Bauman Moscow State Technical University

  • Aleksei Matanin

    • FMN Laboratory, Bauman Moscow State Technical University

  • Alina Dobronosova

    • Dukhov Automatics Research Institute, (VNIIA)

  • Daria Ezenkova

    • FMN Laboratory, Bauman Moscow State Technical University

  • Elizaveta Il'inichna Malevannaya

    • Dukhov Automatics Research Institute, (VNIIA)

  • Ilya Besedin

    • National University of Science and Technology

  • Olga Sorokina

    • Dukhov Automatics Research Institute, (VNIIA)

  • Lucia Almirovna Ganieva

    • Dukhov Automatics Research Institute, (VNIIA)

  • Andronic Michael

    • FMN Laboratory, Bauman Moscow State Technical University

  • Vladimir Vladimirovich Echeistov

    • FMN Laboratory, Bauman Moscow State Technical University

  • Alexander Vyacheslavovich Zverev

    • Dukhov Automatics Research Institute, (VNIIA)

  • Dmitriy Sergeevich Yakovlev

    • Institute of Solid State Physics, Russian Academy of Sciences

  • Ilya Rodionov

    • FMN Laboratory, Bauman Moscow State Technical University