Understanding decoherence mechanisms in tantalum-based superconducting qubits
ORAL
Abstract
Tantalum is a promising material platform for superconducting resonators and qubits, with longer coherence times than other commonly used materials including Nb and Al. In this work, we demonstrate that pure α-tantalum can be grown on silicon either with a Nb seed layer at ambient temperature, or without a seed layer at high substrate temperatures. We perform extensive materials characterization including XPS, XRD, SEM, and cross-sectional TEM to understand the characteristics of α-tantalum on silicon. We fabricate superconducting qubits on such films and correlate changes in the fabrication process with changes in both the materials properties and cryogenic device performance. The work here will provide a pathway to fabricate high coherence superconducting qubits based on tantalum on silicon.
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Presenters
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Candice Kang
University of California, Berkeley
Authors
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Candice Kang
University of California, Berkeley
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Larry Chen
University of California, Berkeley
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Maria Virginia P Altoe
Lawrence Berkeley National Laboratory
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Kan-Heng Lee
Lawrence Berkeley National Laboratory
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Christian Jünger
Lawrence Berkeley National Laboratory, University of California, Berkeley
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Trevor Chistolini
University of California, Berkeley
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D. Frank Ogletree
Lawrence Berkeley National Laboratory, Molecular Foundry, Lawrence Berkeley National Laboratory
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Chengyu Song
Lawrence Berkeley National Laboratory
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David I Santiago
Lawrence Berkeley National Laboratory
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Irfan Siddiqi
University of California, Berkeley, Lawrence Berkeley National Laboratory