Optimal gauge for the multimode Rabi model in circuit QED

Autor:	David P. DiVincenzo, Fabian Hassler, Marco Roth
Rok vydání:	2019
Předmět:	Physics Quantum Physics Multi-mode optical fiber Truncation High Energy Physics::Lattice Anharmonicity FOS: Physical sciences Gauge (firearms) Resonator Quantum electrodynamics ddc:530 Quantum Physics (quant-ph) Subspace topology
Zdroj:	Physical review research 1(3), 033128 (2019). doi:10.1103/PhysRevResearch.1.033128
ISSN:	2643-1564
DOI:	10.1103/physrevresearch.1.033128
Popis:	In circuit QED, a Rabi model can be derived by truncating the Hilbert space of the anharmonic qubit coupled to a linear, reactive environment. This truncation breaks the gauge invariance present in the full Hamiltonian. We analyze the determination of an optimal gauge such that the differences between the truncated and the full Hamiltonian are minimized. Here, we derive a simple criterion for the optimal gauge. We find that it is determined by the ratio of the anharmonicity of the qubit to an averaged environmental frequency. We demonstrate that the usual choices of flux and charge gauge are not necessarily the preferred options in the case of multiple resonator modes. Comment: 4 pages, 3 figures. Includes 3 pages of supplementary material
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3ceb6fdc5fcceaf844409d377d1c903c https://doi.org/10.1103/physrevresearch.1.033128 Zobrazit plný text záznamu