_version_ 1866915700418805760
author Kim, Taeyoon
Roy, Tanay
You, Xinyuan
Li, Andy C. Y.
Lamm, Henry
Pronitchev, Oleg
Bal, Mustafa
Garattoni, Sabrina
Crisa, Francesco
Bafia, Daniel
Kurkcuoglu, Doga
Pilipenko, Roman
Heidler, Paul
Bornman, Nicholas
van Zanten, David
Zorzetti, Silvia
Harnik, Roni
Murthy, Akshay
Lunin, Andrei
Belomestnykh, Sergey
Zhu, Shaojiang
Wang, Changqing
Vallieres, Andre
Huang, Ziwen
Koch, Jens
Grassellino, Anna
Chakram, Srivatsan
Romanenko, Alexander
Lu, Yao
author_facet Kim, Taeyoon
Roy, Tanay
You, Xinyuan
Li, Andy C. Y.
Lamm, Henry
Pronitchev, Oleg
Bal, Mustafa
Garattoni, Sabrina
Crisa, Francesco
Bafia, Daniel
Kurkcuoglu, Doga
Pilipenko, Roman
Heidler, Paul
Bornman, Nicholas
van Zanten, David
Zorzetti, Silvia
Harnik, Roni
Murthy, Akshay
Lunin, Andrei
Belomestnykh, Sergey
Zhu, Shaojiang
Wang, Changqing
Vallieres, Andre
Huang, Ziwen
Koch, Jens
Grassellino, Anna
Chakram, Srivatsan
Romanenko, Alexander
Lu, Yao
contents Superconducting radio-frequency (SRF) cavities offer a promising platform for quantum computing due to their long coherence times, yet integrating nonlinear elements like transmons for control often introduces additional loss. We report a multimode quantum system based on a 2-cell elliptical shaped SRF cavity, comprising two cavity modes weakly coupled to an ancillary transmon circuit, designed to preserve coherence while enabling efficient control of the cavity modes. We mitigate the detrimental effects of the transmon decoherence through careful design optimization that reduces transmon-cavity couplings and participation in the dielectric substrate and lossy interfaces, to achieve single-photon lifetimes of 20.6 ms and 15.6 ms for the two modes, and a pure dephasing time exceeding 40 ms. This marks an order-of-magnitude improvement over prior 3D multimode memories. Leveraging sideband interactions and novel error-resilient protocols, including measurement-based correction and post-selection, we achieve high-fidelity control over quantum states. This enables the preparation of Fock states up to $N = 20$ with fidelities exceeding 95%, the highest reported to date to the authors' knowledge, as well as two-mode entanglement with an estimated coherence-limited fidelities of 99.9% after post-selection. These results establish our platform as a robust foundation for quantum information processing, allowing for future extensions to high-dimensional qudit encodings.
format Preprint
id arxiv_https___arxiv_org_abs_2506_03286
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Ultracoherent superconducting cavity-based multiqudit platform with error-resilient control
Kim, Taeyoon
Roy, Tanay
You, Xinyuan
Li, Andy C. Y.
Lamm, Henry
Pronitchev, Oleg
Bal, Mustafa
Garattoni, Sabrina
Crisa, Francesco
Bafia, Daniel
Kurkcuoglu, Doga
Pilipenko, Roman
Heidler, Paul
Bornman, Nicholas
van Zanten, David
Zorzetti, Silvia
Harnik, Roni
Murthy, Akshay
Lunin, Andrei
Belomestnykh, Sergey
Zhu, Shaojiang
Wang, Changqing
Vallieres, Andre
Huang, Ziwen
Koch, Jens
Grassellino, Anna
Chakram, Srivatsan
Romanenko, Alexander
Lu, Yao
Quantum Physics
Superconducting radio-frequency (SRF) cavities offer a promising platform for quantum computing due to their long coherence times, yet integrating nonlinear elements like transmons for control often introduces additional loss. We report a multimode quantum system based on a 2-cell elliptical shaped SRF cavity, comprising two cavity modes weakly coupled to an ancillary transmon circuit, designed to preserve coherence while enabling efficient control of the cavity modes. We mitigate the detrimental effects of the transmon decoherence through careful design optimization that reduces transmon-cavity couplings and participation in the dielectric substrate and lossy interfaces, to achieve single-photon lifetimes of 20.6 ms and 15.6 ms for the two modes, and a pure dephasing time exceeding 40 ms. This marks an order-of-magnitude improvement over prior 3D multimode memories. Leveraging sideband interactions and novel error-resilient protocols, including measurement-based correction and post-selection, we achieve high-fidelity control over quantum states. This enables the preparation of Fock states up to $N = 20$ with fidelities exceeding 95%, the highest reported to date to the authors' knowledge, as well as two-mode entanglement with an estimated coherence-limited fidelities of 99.9% after post-selection. These results establish our platform as a robust foundation for quantum information processing, allowing for future extensions to high-dimensional qudit encodings.
title Ultracoherent superconducting cavity-based multiqudit platform with error-resilient control
topic Quantum Physics
url https://arxiv.org/abs/2506.03286