Boundary Conditions in Circuit QED Dispersive Readout
Published:Dec 30, 2025 21:10
•1 min read
•ArXiv
Analysis
This paper offers a novel perspective on circuit QED dispersive readout by framing it through the lens of boundary conditions. It provides a first-principles derivation, connecting the qubit's transition frequencies to the pole structure of a frequency-dependent boundary condition. The use of spectral theory and the derivation of key phenomena like dispersive shift and vacuum Rabi splitting are significant. The paper's analysis of parity-only measurement and the conditions for frequency degeneracy in multi-qubit systems are also noteworthy.
Key Takeaways
Reference
“The dispersive shift and vacuum Rabi splitting emerge from the transcendental eigenvalue equation, with the residues determined by matching to the splitting: $δ_{ge} = 2Lg^2ω_q^2/v^4$, where $g$ is the vacuum Rabi coupling.”