Physical Review Letters · 2009 · 160 citations · 26 references
Natural SciencesPhysicsCondensed Matter PhysicsQuantum MechanicsSpectroscopyQuantum OpticsQuantum PhysicsQuantum SimulationSuperconducting MaterialsSuperconducting QubitsJosephson JunctionsLevel CrossingsLevelsPhase QubitsResonant CouplingThree-level Models
The Autler‑Townes effect describes the splitting of a probe absorption peak in a three‑level quantum system when a resonant coupling field is applied to one transition. We observe this splitting in a superconducting Josephson phase qubit, and both a simple three‑level model and a detailed simulation with dissipation and higher levels reproduce the measured spectroscopy peaks.
When a three-level quantum system is irradiated by an intense coupling field resonant with one of the three possible transitions, the absorption peak of an additional probe field involving the remaining level is split. This process is known in quantum optics as the Autler-Townes effect. We observe these phenomena in a superconducting Josephson phase qubit, which can be considered an ``artificial atom'' with a multilevel quantum structure. The spectroscopy peaks can be explained reasonably well by a simple three-level Hamiltonian model. Simulation of a more complete model (including dissipation, higher levels, and cross coupling) provides excellent agreement with all of the experimental data.
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Coherent control of macroscopic quantum states in a single-Cooper-pair box