Anomalous Fano resonance of massive Dirac particle through a time-dependent barrier

¹ Institute of Applied Physics and Computational Mathematics - Beijing 100088, China
² School of Naval Architecture and Ocean Engineering, Zhejiang Ocean University - Zhoushan 316022, China
³ Key Laboratory of Oceanographic Big Data Mining Application of Zhejiang Province, Zhejiang Ocean University Zhoushan, Zhejiang 316022, China
⁴ HEDPS, Center for Applied Physics and Technology, Peking University - 100084 Beijing, China

^(a) lbfu@iapcm.ac.cn

Received: 27 March 2015
Accepted: 12 June 2015

Abstract

As is well known Fano resonance arises from the interference between a localized state and a continuum state. Using the standard Floquet theory and the scattering matrix method, we study theoretically the massive Dirac particle transmission over a quantum barrier with an oscillating field. It is found that the massive relativistic particles can generate not only normal Fano resonance in the transmission due to the interference between a localized state (bound state) and the continuum state, but also anomalous Fano resonance due to the interference between a delocalized state (extended state) and the continuum state. The dependence of line shapes on driving parameters for these two kinds of Fano resonances is quite different. For normal Fano resonance the asymmetry parameter is approximately proportional to a power law of the amplitude of the oscillating field, while for the anomalous Fano resonance the asymmetry parameters change slightly with different oscillation amplitudes. In practice, the anomalous Fano resonance can be identified by observing asymmetry parameters in experiment.