Data for Nature Physics manuscript, "Strong parametric dispersive shifts in a statically decoupled two-qubit cavity QED system"

The files within this record represent the data shown in the Nature Physics article, "Strong parametric dispersive shifts in a statically decoupled two-qubit cavity QED system". Descriptions of this data are most detailed within the figure captions of the article. Please download and review the file "3027_README.txt" to learn more. The article abstract reads: Qubits in cavity quantum electrodynamic (QED) architectures are often operated in the dispersive regime, in which the operating frequency of the cavity depends on the energy state of the qubit, and vice versa. The ability to tune these dispersive shifts provides additional options for performing either quantum measurements or logical manipulations. Here, we couple two transmon qubits to a lumped-element cavity through a shared SQUID. Our design balances the mutual capacitive and inductive circuit components so that both qubits are statically decoupled from the cavity with low flux sensitivity, offering protection from decoherence processes. Parametric driving of the SQUID flux enables independent, dynamical tuning of each qubit's interaction with the cavity. As a practical demonstration, we perform pulsed parametric dispersive readout of both qubits. The dispersive frequency shifts of the cavity mode follow the theoretically expected magnitude and sign. This parametric approach creates an extensible, tunable cavity QED framework with various future applications, such as entanglement and error correction via multi-qubit parity readout, state and entanglement stabilization, and parametric logical gates.If you have questions regarding this data record, feel free to email me at: raymond.simmonds@nist.gov