Quantum coherent states of mass-imbalanced electron-hole system within optical microcavities

TL;DR

This paper theoretically investigates the complex phase structure of coherent electron-hole-photon states in optical microcavities with mass imbalance, revealing transitions among various condensate states and identifying their spectral signatures.

Contribution

It introduces a self-consistent Hartree-Fock framework to analyze mass-imbalanced electron-hole systems, uncovering new phase transitions and spectral features of polariton condensates.

Findings

Transition from disordered to various condensate states as mass imbalance decreases

Distinct spectral signatures for different condensate phases identified

Emergence of quantum coherent bound states before condensate formation

Abstract

The interplay of the excitoniclike polariton, polariton, and photoniclike polariton coherent states in mass-imbalanced electron-hole systems within optical microcavities is theoretically examined. Utilizing the unrestricted Hartree-Fock approximation, we derive a set of self-consistent equations that evaluate the excitonic and photonic order parameters in a two-band electronic model, accounting equally for both electron-hole Coulomb attraction and light-matter coupling. Analyzing the competition among these condensate order parameters reveals a complex phase structure of coherent states in the ground state. As the mass imbalance is reduced, we observe a transition from a normal disordered electron-hole-photon system to excitoniclike, polariton, and ultimately photoniclike polariton condensation states. The distinct features of these robust condensates can be identified in the momentum distribution of the electron-hole pair amplitude and the photonic density, as well as in the wave-number-resolved photoemission spectra of electrons, holes, and photons. Increasing the excitation density further expands the range of condensation states. Additionally, lowering the mass imbalance leads to the emergence of quantum coherent bound states prior to the formation of robust condensates, which are evidenced by the static and dynamical excitonic and photonic susceptibility functions.