Fatemeh Davoodi

Photonic environments with engineered chirality offer a practical route to coherence control at the nanoscale. We demonstrate that a symmetry‐broken plasmonic honeycomb lattice functions as a directional reservoir that preserves emitter coherence even in the weak‐coupling regime. Using a coupled‐dipole model linked to cascaded‐Lindblad dynamics, we find that spin‐momentum‐locked edge modes mediate unidirectional energy transfer and produce subradiant and superradiant dynamics over mesoscopic distances. Far‐field polarization maps (Stokes S ₃ ) directly trace this phase preservation, while time‐domain simulations reveal sustained collective oscillations beyond the near field. Together, these results establish a design framework for chiral plasmonic interfaces that support coherence‐protected light‐matter interactions, providing an experimentally accessible path toward phase‐stable quantum photonic functionality at ambient conditions.

Topological photonic systems offer a robust platform for guiding light in the presence of disorder, but their interplay with quantum emitters remains a frontier for realizing strongly correlated quantum states. Here, we explore a ring‐shaped Su‐Schrieffer‐Heeger (SSH) photonic lattice interfaced with multiple quantum emitters to control topologically protected chiral quantum dynamics. Using a full microscopic model that includes cascaded Lindblad dynamics and chiral emitter‐bath couplings, we reveal how the topology of the bath mediates nonreciprocal, long‐range interactions between emitters. These interactions lead to rich many‐body spin phenomena, including robust coherence, directional energy transfer, captured by an effective spin Hamiltonian derived from the system’s topology. We show that topological bound states enable unidirectional emission, protect coherence against dissipation, and imprint nontrivial entanglement and mutual information patterns among the emitters. In particular, we showed that under circularly polarized excitation, the emitters not only inherit spin angular momentum from the field but also serve as transducers that coherently launch the spin‐orbit‐coupled topological photonic modes into the far field. Our results establish a direct bridge between topological photonic baths and emergent quantum magnetism, positioning this architecture as a promising testbed for studying chiral quantum optics, topologically protected entangled states, and long‐range quantum coherence.

Topological photonic systems offer a robust platform for guiding light in the presence of disorder, but their interplay with quantum emitters remains a frontier for realizing strongly correlated quantum states. Here, we explore a ring-shaped Su-Schrieffer-Heeger (SSH) photonic lattice interfaced with multiple quantum emitters to control topologically protected chiral quantum dynamics. Using a full microscopic model that includes cascaded Lindblad dynamics and chiral emitter-bath couplings, we reveal how the topology of the bath mediates nonreciprocal, long-range interactions between emitters. These interactions lead to rich many-body spin phenomena, including robust coherence, directional energy transfer, captured by an effective spin Hamiltonian derived from the system’s topology. We show that topological bound states enable unidirectional emission, protect coherence against dissipation, and imprint nontrivial entanglement and mutual information patterns among the emitters. In particular, we showed that under circularly polarized excitation, the emitters not only inherit spin angular momentum from the field but also serve as transducers that coherently launch the spin-orbit-coupled topological photonic modes into the far field. Our results establish a direct bridge between topological photonic baths and emergent quantum magnetism, positioning this architecture as a promising testbed for studying chiral quantum optics, topologically protected entangled states, and long-range quantum coherence.

Topological photonic systems offer a robust platform for guiding light in the presence of disorder, but their interplay with quantum emitters remains a frontier for realizing strongly correlated quantum states. Here, we explore a ring-shaped Su-Schrieffer-Heeger (SSH) photonic lattice interfaced with multiple quantum emitters to control topologically protected chiral quantum dynamics. Using a full microscopic model that includes cascaded Lindblad dynamics and chiral emitter-bath couplings, we reveal how the topology of the bath mediates nonreciprocal, long-range interactions between emitters. These interactions lead to rich manybody spin phenomena, including robust coherence, directional energy transfer, and emergent double Néel ordering, captured by an effective spin Hamiltonian derived from the system topology. We show that topological bound states enable unidirectional emission, protect coherence against dissipation, and imprint nontrivial entanglement and mutual information patterns among the emitters. In particular, we showed that under circularly polarized excitation, the emitters not only inherit spin angular momentum from the field but also serve as transducers that coherently launch the spin-orbit-coupled topological photonic modes into the far field. Our results establish a direct bridge between topological photonic baths and emergent quantum magnetism, positioning this architecture as a promising testbed for studying chiral quantum optics, topologically protected entangled states, and long-range quantum coherence.

Long lived coherent quasiparticles are a promising foundation for novel quantum technologies, where maintaining quantum coherence is crucial. Decoherence, driven by finite emitter lifetimes, remains a central challenge in quantum computing. Here, we control the dynamics of spatially separated quantum emitters via preserving their phase information by introducing a topological waveguide as a robust chiral reservoir. Incoherent quantum emitters randomly positioned near a perturbed honeycomb plasmonic interface and couple to the mutual topological interface mode. Using the S3 Stokes parameter, we trace farfield polarization patterns that reflect emitter coherence and spin-momentum locking. We show that even weakly coupled emitters exhibit coherent excitation and imprint phase on the emission. Time domain dynamics reveal signatures of superradiance and subradiance that correlate with spatial interference in S3. These spatial temporal features confirm that the observed polarization patterns arise from coherent quantum manybody dynamics, not classical interference. This challenges the conventional dichotomy between incoherent and coherent regimes, revealing that topological chiral photonic environments mediate long-range quantum correlations beyond standard waveguide QED.

Long-lived coherent quasiparticles are a promising foundation for novel quantum technologies, where maintaining quantum coherence is crucial. Decoherence, driven by finite emitter lifetimes, remains a central challenge in quantum computing. Here, we control the dynamics of spatially separated quantum emitters via preserving their phase information by introducing a topological waveguide as a robust chiral reservoir. Incoherent quantum emitters randomly positioned near a perturbed honeycomb plasmonic interface and couple to the mutual topological interface mode. Using the S₃ Stokes parameter, we trace far-field polarization patterns that reflect emitter coherence and spin–momentum locking. We show that even weakly coupled emitters exhibit coherent excitation and imprint phase on the emission. Time-domain dynamics reveal signatures of superradiance and subradiance that correlate with spatial interference in S_3. These spatial-temporal features confirm that the observed polarization patterns arise from coherent quantum many-body dynamics, not classical interference. This challenges the conventional dichotomy between incoherent and coherent regimes, revealing that topological chiral photonic environments mediate long-range quantum correlations beyond standard waveguide QED.

Topological plasmonics combines principles of topology and plasmonics to provide new methods for controlling light, analogous to topological edge states in photonics. However, designing such topological states remains challenging due to the complexity of the high-dimensional design space. We present a novel method that uses supervised, physics-informed deep learning and surrogate modeling to design topological devices for desired wavelengths. By embedding physical constraints in the neural network's training, our model efficiently explores the design space, significantly reducing simulation time. Additionally, we use nonplanar wavefront excitations to probe topologically protected plasmonic modes, making the design and training process nonlinear. Using this approach, we design a topological device with unidirectional edge modes in a ring resonator at specific operational frequencies. Our method reduces computational cost and time while maintaining high accuracy, highlighting the potential of combining machine learning and advanced techniques for photonic device innovation.

Copper monosulfide (CuS), also known as covellite, displays exceptional optoelectronic characteristics, exhibiting both plasmonic and photonic absorption in its monolithic nanomaterial form. It is classified as a hybrid metallic‐semiconducting material and a natural hyperbolic material with a distinctive crystal structure. Nanostructured CuS has been demonstrated to support localized surface plasmon resonances (LSPR) in the near‐infrared spectral range. Here, the phenomenon of near‐infrared (NIR) to visible electromagnetic field localization in ultrathin crystalline quasi‐2D CuS nanocrystals is revealed. This is achieved by mapping LSPRs in a range of CuS structures using high‐resolution electron energy‐loss spectroscopy in combination with cathodoluminescence spectroscopy. In addition to LSPRs, a range of photonic modes in the visible and ultraviolet spectral ranges is identified in colloidally defined single‐crystalline nanostructures, with numerical simulations providing supporting evidence. Finally, CuS nanocrystals exhibit visible NIR light emission within the range of 600–900 nm when excited by an electron beam. Altogether, these properties make CuS nanocrystals highly suitable for applications in telecommunications, sensing, and nanophotonics.

Topological plasmonics offers new ways to manipulate light by combining concepts from topology and plasmonics, similar to topological edge states in photonics. However, designing such topological states remains challenging due to the complexity of the high dimensional design space. We present a novel method that uses supervised, physics informed deep learning and surrogate modeling to design topological devices for specific wavelengths. By embedding physical constrains in the neural network training, our model efficiently explores the design space, significantly reducing simulation time. Additionally, we use non planar wavefront excitations via electron beams to probe topologically protected plasmonic modes, making the design and training process nonlinear. Using this approach, we design a topological device with unidirectional edge modes in a ring resonator at specific operational frequencies. Our method reduces computational cost and time while maintaining high accuracy, highlighting the potential of combining machine learning and advanced techniques for photonic device innovation.

Chiral plasmonic nanostructures possess a chiroptical response orders of magnitude stronger than that of natural biomolecular systems, making them highly promising for a wide range of biochemical, medical, and physical applications. Despite extensive efforts to artificially create and tune the chiroptical properties of chiral nanostructures through compositional and geometrical modifications, a fundamental understanding of their underlying mechanisms remains limited. In this study, we present a comprehensive investigation of individual gold nanohelices by using advanced analytical electron microscopy techniques. Our results, as determined by angle-resolved cathodoluminescence polarimetry measurements, reveal a strong correlation between the circular polarization state of the emitted far-field radiation and the handedness of the chiral nanostructure in terms of both its dominant circularity and directional intensity distribution. Further analyses, including electron energy-loss measurements and numerical simulations, demonstrate that this correlation is driven by longitudinal plasmonic modes that oscillate along the helical windings, much like straight nanorods of equal strength and length. However, due to the three-dimensional shape of the structures, these longitudinal modes induce dipolar transverse modes with charge oscillations along the short axis of the helices for certain resonance energies. Their radiative decay leads to observed emission in the visible range. Our findings provide insight into the radiative properties and underlying mechanisms of chiral plasmonic nanostructures and enable their future development and application in a wide range of fields, such as nano-optics, metamaterials, molecular physics, biochemistry, and, most promising, chiral sensing via plasmonically enhanced chiral optical spectroscopy techniques.