Quadruply Bonded Mo$_2$ Molecules Acting as an Inborn Emitter-Resonator Quantum System in Free Space

TL;DR

This paper demonstrates that quadruply-bonded Mo₂ molecules can act as independent emitter-resonator quantum systems in free space, enabling observation of quantum phenomena and advancing quantum optics and molecular physics.

Contribution

It introduces Mo₂ molecules as novel free-space emitter-resonator quantum systems with observable quantum effects like Rabi splitting and photon antibunching.

Findings

Mo₂ molecules trap visible photons under ambient conditions

Electronic and vibrational states are coherently coupled with scattered photons

Quantum phenomena such as Rabi doublet and Mollow triplet are observed

Abstract

In recent decades, significant progress has been made in construction and study of individual quantum systems consisting of the basic single matter and energy particles, i.e., atoms and photons, which show great potentials in quantum computation and communication. Here, we demonstrate that the quadruply-bonded Mo$_2$ unit of the complex can trap photons of visible light under ambient conditions, producing intense local electromagnetic (EM) field that features squeezed states, photon antibunching, and vacuum Rabi splitting. Our results show that both the electronic and vibrational states of the Mo$_2$ molecule are modified by coherent coupling with the scattered photons of the Mo$_2$ unit, as evidenced by the Rabi doublet4 and the Mollow triplet in the incoherent resonance fluorescence and the Raman spectra. The Mo$_2$ molecule, acting as an independent emitter-resonator integrated quantum system, allows optical experiments to be conducted in free space, enabling fundamental quantum phenomena to be observed through conventional spectroscopic instrumentation. This provides a new platform for study of field effects and quantum electrodynamics (QED) in the optical domain. The insights gained from this study advance our understanding in metal-metal bond chemistry, molecular physics and quantum optics, with applications in quantum information processing, optoelectronic devices and control of chemical reactivity.