Three-type Fano interference controlled by the phase transition of Eu3+/Pr3+:YPO4

Abstract

Abstract We study the Fano interference from different phase transitions of Eu3+:YPO4 and Pr3+:YPO4 crystals through simultaneous detection of bright and dark states. For this study, we employed tetragonal (T), hexahedral (H), and (H + T)-phases of YPO4 crystals. The Fano interfering bright and dark states are classified based on dressed spontaneous parametric four-wave mixing, dressed multi-order fluorescence, and hybrid signal regimes. Further, the Fano interference between conti-nuous and discrete states can be controlled from partly-(constructive–destructive)-interference through a phase transition, nonlinear phase, and dressing. The (H + T)-phase Pr3+:YPO4 suggests more obvious Fano interference in contrast to T- or H-phase Pr3+:YPO4. We report that the Pr3+:YPO4 and Eu3+:YPO4 demonstrates the dressed multi-level- and dressed single-level Fano interference, respectively, with further three types of Fano interference that can be distinguished at different time delays. The experimental measurement agrees with theoretical simulations. Such results may be used for the design of new types of quantum electronic or spintronic devices such as Fano-transistors.