Observation of Bloch--Siegert shifts in the 2$sup 2$S/sub 1/2/ - 2$sup 2$P/ sub 1/2/ microwave resonance in atomic hydrogen

Jinyi Zhang, Christoph Eigen, Raphael Lopes +5 more

David A. Andrews, G. Newton

David A. Andrews, G Newton

Radio-frequency power shifts in the 2 2 S 1/2 -2 2 P 1/2 microwave resonance in atomic hydrogen have been measured and compared with the results of a numerical integration for the two- and three-level situations. Effects due to the initial phase of the RF field, the finite size of the atomic beam and its trajectory have been included in the numerical integration.

Jani Tuorila, Matti Silveri, Mika A. Sillanpää +3 more

A superconducting qubit was driven in an ultrastrong fashion by an oscillatory microwave field, which was created by coupling via the nonlinear Josephson energy. The observed Stark shifts of the "atomic" levels are so pronounced that corrections even beyond the lowest-order Bloch-Siegert shift are needed to properly explain the measurements. The quasienergies of the dressed two-level system were probed by resonant absorption via a cavity, and the results are in agreement with a calculation based on the Floquet approach.

Yu. L. Sokolov

George Toh, Dionysis Antypas, Daniel S. Elliott