Quantum Interference and Optical Tuning of Self-Trapped Exciton State in Double Halide Perovskite

TL;DR

This paper investigates the hybrid nature of self-trapped excitons in a double halide perovskite, demonstrating optical tuning via quantum interference effects, which advances understanding and control of excitonic states for photonic applications.

Contribution

It provides the first experimental and theoretical evidence of exciton-phonon hybrid states in Cs2Ag0.4Na0.6InCl6 and shows how to tune these states with laser parameters.

Findings

Detection of Fano resonance indicating hybrid exciton-phonon states

Ability to tune hybrid states with laser energy and intensity

Foundation for controlling excitonic states in perovskites

Abstract

Self-trapped excitons (STEs), renowned for their unique radiative properties, have been harnessed in diverse photonic devices. Yet, a full comprehension and manipulation of STEs remain elusive. In this study, we present novel experimental and theoretical evidence of the hybrid nature and optical tuning of the STEs state in Cs2Ag0.4Na0.6InCl6. The detection of Fano resonance in the laser energy-dependent Raman and photoluminescence spectra indicates the emergence of an exciton-phonon hybrid state, a result of the robust quantum interference between the discrete phonon and continuous exciton states. Moreover, we showcase the ability to continuously adjust this hybrid state with the energy and intensity of the laser field. These significant findings lay the foundation for a comprehensive understanding of the nature of STE and its potential for state control.