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Bibliographic Details
Main Authors: Oriani, Andrew E., Zhao, Fang, Roy, Tanay, Anferov, Alexander, He, Kevin, Agrawal, Ankur, Banerjee, Riju, Chakram, Srivatsan, Schuster, David I.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2403.00286
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author Oriani, Andrew E.
Zhao, Fang
Roy, Tanay
Anferov, Alexander
He, Kevin
Agrawal, Ankur
Banerjee, Riju
Chakram, Srivatsan
Schuster, David I.
author_facet Oriani, Andrew E.
Zhao, Fang
Roy, Tanay
Anferov, Alexander
He, Kevin
Agrawal, Ankur
Banerjee, Riju
Chakram, Srivatsan
Schuster, David I.
contents Group-V materials such as niobium and tantalum have become popular choices for extending the performance of circuit quantum electrodynamics (cQED) platforms allowing for quantum processors and memories with reduced error rates and more modes. The complex surface chemistry of niobium however makes identifying the main modes of decoherence difficult at millikelvin temperatures and single-photon powers. We use niobium coaxial quarter-wave cavities to study the impact of etch chemistry, prolonged atmospheric exposure, and the significance of cavity conditions prior to and during cooldown, in particular niobium hydride evolution, on single-photon coherence. We demonstrate cavities with quality factors of Q_int>1.4X10^9 in the single-photon regime, a 15 fold improvement over aluminum cavities of the same geometry. We rigorously quantify the sensitivity of our fabrication process to various loss mechanisms and demonstrate a 2-4X reduction in the two-level system (TLS) loss tangent and a 3-5X improvement in the residual resistance over traditional BCP etching techniques. Finally, we demonstrate transmon integration and coherent cavity control while maintaining a cavity coherence of 11.3ms. The accessibility of our method, which can easily be replicated in academic-lab settings, and the demonstration of its performance mark an advancement in 3D cQED.
format Preprint
id arxiv_https___arxiv_org_abs_2403_00286
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Niobium coaxial cavities with internal quality factors exceeding 1.5 billion for circuit quantum electrodynamics
Oriani, Andrew E.
Zhao, Fang
Roy, Tanay
Anferov, Alexander
He, Kevin
Agrawal, Ankur
Banerjee, Riju
Chakram, Srivatsan
Schuster, David I.
Quantum Physics
Superconductivity
Group-V materials such as niobium and tantalum have become popular choices for extending the performance of circuit quantum electrodynamics (cQED) platforms allowing for quantum processors and memories with reduced error rates and more modes. The complex surface chemistry of niobium however makes identifying the main modes of decoherence difficult at millikelvin temperatures and single-photon powers. We use niobium coaxial quarter-wave cavities to study the impact of etch chemistry, prolonged atmospheric exposure, and the significance of cavity conditions prior to and during cooldown, in particular niobium hydride evolution, on single-photon coherence. We demonstrate cavities with quality factors of Q_int>1.4X10^9 in the single-photon regime, a 15 fold improvement over aluminum cavities of the same geometry. We rigorously quantify the sensitivity of our fabrication process to various loss mechanisms and demonstrate a 2-4X reduction in the two-level system (TLS) loss tangent and a 3-5X improvement in the residual resistance over traditional BCP etching techniques. Finally, we demonstrate transmon integration and coherent cavity control while maintaining a cavity coherence of 11.3ms. The accessibility of our method, which can easily be replicated in academic-lab settings, and the demonstration of its performance mark an advancement in 3D cQED.
title Niobium coaxial cavities with internal quality factors exceeding 1.5 billion for circuit quantum electrodynamics
topic Quantum Physics
Superconductivity
url https://arxiv.org/abs/2403.00286