Coherence effects of the strongly-coupled optical polaron-level qubit in a quantum well with asymmetrical semi-exponential potential

Abstract

Abstract A theoretically investigation of the effects of barrier height of an asymmetrical semi-exponential confinement potential (ASECP) quantum well (QW) and the range of the ASECP on vibration frequency, first excited state (FES) energy, excitation energy and coherence time in the ASECP QW is performed. In order to determine the relationship between these factors, the linear combination operator, twice unitary transformations and Fermi Golden Rule methods are used. The vibration frequency, FES energy and excitation energy of the strong-coupled polaron are derived, as well as the qubit coherence time in the ASECP QW when the barrier height of the QW and the ASECP range are varied. It is found that these physical quantities are increasing functions of the barrier height, whereas they are decaying functions of the range. Furthermore, the coherence time is a decaying function with increased barrier height and an increasing function with enhanced range.