Engineering Purely Nonlinear Coupling between Superconducting Qubits Using a Quarton
Name
PhysRevLett.127.050502.pdf
Description
Published version
Size
642.42 KB
Format
Adobe PDF
Checksum (MD5)
5fd50ee7556ef070bbeb11430f5e537d
Author(s)
Ye, Yufeng
Peng, Kaidong
Naghiloo, Mahdi
Cunningham, Gregory
O’Brien, Kevin P
Date Issued
2021
Journal
Physical Review Letters
Publisher
American Physical Society (APS)
Citation
Ye, Yufeng, Peng, Kaidong, Naghiloo, Mahdi, Cunningham, Gregory and O’Brien, Kevin P. 2021. "Engineering Purely Nonlinear Coupling between Superconducting Qubits Using a Quarton." Physical Review Letters, 127 (5).
Version
Final published version
Abstract
Strong nonlinear coupling of superconducting qubits and/or photons is a critical building block for quantum information processing. Because of the perturbative nature of the Josephson nonlinearity, linear coupling is often used in the dispersive regime to approximate nonlinear coupling. However, this dispersive coupling is weak and the underlying linear coupling mixes the local modes, which, for example, distributes unwanted self-Kerr nonlinearity to photon modes. Here, we use the quarton to yield purely nonlinear coupling between two linearly decoupled transmon qubits. The quarton's zero ϕ^{2} potential enables an ultrastrong gigahertz-level cross-Kerr coupling, which is an order of magnitude stronger compared to existing schemes, and the quarton's positive ϕ^{4} potential can cancel the negative self-Kerr nonlinearity of qubits to linearize them into resonators. This ultrastrong cross-Kerr coupling between bare modes of qubit-qubit, qubit-photon, and even photon-photon is ideal for applications such as single microwave photon detection, ultrafast two-qubit gates, and readout.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Research Laboratory of Electronics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PHYSREVLETT.127.050502
