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Multiphoton transitions in a macroscopic quantum two-state system

S. Saito·M. Thorwart·H. Tanaka·M. Ueda·H. Nakano·K. Semba·H. Takayanagi
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Abstract

We have observed multiphoton transitions between two macroscopic quantum-mechanical superposition states formed by two opposite circulating currents in a superconducting loop with three Josephson junctions. Resonant peaks and dips of up to three-photon transitions were observed in spectroscopic measurements when the system was irradiated with a strong RF-photon field. The widths of the multiphoton absorption dips are shown to scale with the Bessel functions in agreement with theoretical predictions derived from the Bloch equation or from a spin-boson model.

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S. Saito, M. Thorwart, H. Tanaka, M. Ueda, H. Nakano, K. Semba, H. Takayanagi. 2004-03-17. Multiphoton transitions in a macroscopic quantum two-state system. https://doi.org/10.1103/physrevlett.93.037001

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