arXiv subjects

Zi Cong He

Publications and source records attributed to Zi Cong He.

4 recordsLinked to original sources

arXiv2026

Strong, Mode-Selective Evxciton-Photon Coupling Driven by Polariton Scattering in the Mo2 Complexes at Ambient Conditions

Quadruply bonded Mo2 complexes provide a distinctive molecular platform in which multiple two-level electronic transitions interact with quantized scattering modes under ambient conditions. Here we show that, in the Mo2 complexes, the intrinsic photonic modes selectively couple to molecular excitations, including the characteristic delta-delta(star), ligand to metal charge transfer (LMCT) and metal to ligand charge transfer (MLCT) transitions, to form the well-resolved exciton-photon hybrid states. By combining steady-state absorption, resonance fluorescence, and ultrafast transient spectroscopies, we identify distinct polaritonic branches associated with these electronic manifolds, with coupling strengths spanning the strong and ultrastrong regimes (g/omega0 up to 0.1). Mode-selective coupling accounts for the pronounced spectral reorganization for the singly oxidized complexes, including the emergence of absorption valleys and sidebands of the associated resonances in the steady-state spectra, characteristic polaritonic emissions in the photoluminescence spectra, and long-lived low-energy hybrid states in the transient spectra. These results support the picture that the Mo2 unit functions as an integrated molecular resonator whose intrinsic quantized field selectively drives and redistributes molecular excitations. This work strengthens the emerging view of bonded dimetal complexes as ambient-condition molecular quantum systems and provides a chemically defined platform for exploring polaritonic chemistry.

physics.optics↗

arXiv2026

Quadruply Bonded Mo2 Molecules: An Innate Emitter-Resonator Quantum System in Free Space

In recent decades, significant progress has been made in constructing and studying individual quantum systems based on two level atoms (molecules) and photons. Here we demonstrate that the quadruply bonded Mo2 unit, with a MoMo bond distance as short as 2.1A, functions as an innate emitter resonator molecular quantum system capable of trapping visible light photons between the two molybdenum atoms under ambient conditions, thereby generating an intense quantized local electromagnetic field with an extremely small mode volume. The resonance fluorescence spectra of three Mo2 complexes indicate that the intermetallic Mo-Mo charge transfer transition is coherently coupled to the local scattering field, exhibiting vacuum Rabi splitting and Mollow triplets. Resonant coupling of single molecules and N-molecule ensembles to the scattered light through sideband excitation produces a sequence of discrete optical modes spanning a broad wavelength range, with polaritonic transitions identical to those observed in Ni2 based systems. These results establish the Mo2 molecule as an independent emitter resonator integrated quantum system that enables quantum optical experiments in free space using conventional spectroscopic instrumentation. This work extends quantum electrodynamics into molecular science, providing new insights into metal metal bonding, molecular physics, and light matter interactions.

quant-ph↗

arXiv2025

Quantization of Visible Light by a Ni$_2$ Molecular Optical Resonator

The quantization of an optical field is a frontier in quantum optics with implications for both fundamental science and technological applications. Here, we demonstrate that a dinickel complex (Ni$_2$) traps and quantizes classical visible light, behaving as an individual quantum system or the Jaynes Cummings molecule.The composite system forms through coherently coupling the two level NiNi charge transfer transition with the local scattering field, which produces nonclassical light featuring photon anti bunching and squeezed states, as verified by a sequence of discrete photonic modes in the incoherent resonance fluorescence. Notably, in this Ni$_2$ system, the collective coupling of N molecule ensembles scales as N, distinct from the Tavis-Cummings model, which allows easy achievement of ultrastrong coupling. This is exemplified by a vacuum Rabi splitting of 1.2 eV at the resonance (3.25 eV) and a normalized coupling rate of 0.18 for the N = 4 ensemble. The resulting quantum light of single photonic modes enables driving the molecule field interaction in cavity free solution, which profoundly modifies the electronic states. Our results establish Ni$_2$ as a robust platform for quantum optical phenomena under ambient conditions, offering new pathways for molecular physics, polaritonic chemistry and quantum information processing.

quant-ph↗

arXiv2025

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

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.

quant-ph↗