Quantum acoustics with a released thickness-mode mechanical resonator
Bathala, Sharan Mourya
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/132710
Description
Title
Quantum acoustics with a released thickness-mode mechanical resonator
Author(s)
Bathala, Sharan Mourya
Issue Date
2025-12-11
Director of Research (if dissertation) or Advisor (if thesis)
Fang, Kejie
Department of Study
Electrical & Computer Eng
Discipline
Electrical & Computer Engr
Degree Granting Institution
University of Illinois Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
Quantum Acoustics
Quantum Optomechanics
Abstract
The circuit quantum acoustodynamics (cQAD) platform integrates the strong nonlinearity of superconducting Josephson elements with high-quality mechanical resonators, enabling potential applications in quantum memories, transducers, and sensors. A central challenge in this field is achieving strong electromechanical coupling between the mechanical resonator and the superconducting qubit, while preserving the resonator’s high quality factor. Strong coupling generally favors small mode volumes and often involves metallic components that introduce additional dissipation channels and fabrication complexity. Conversely, larger mode volumes reduce the coupling strength because only the portion of the resonator proximate to the qubit couples effectively. In this work, we address this trade-off by developing a released thickness-mode mechanical resonator based on an aluminum nitride (AlN)-on-silicon (Si) platform. The device is designed to achieve strong piezoelectric coupling to a superconducting qubit. The resonator, with a lateral dimension of approximately $200\times200$ $\mu m^2$, is fully released from the Si substrate to minimize clamping losses. Theoretical analysis predicts coupling strengths exceeding 10 MHz between the qubit’s electric field and the resonator’s intrinsic piezoelectric mode. The design, coupling mechanism, and fabrication process of the released AlN thickness-mode resonator are presented in detail. This approach simplifies fabrication, and provides a scalable path toward hybrid quantum systems with high coherence and large electromechanical coupling strengths.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
