arXiv subjects

Seungkyun Park

Publications and source records attributed to Seungkyun Park.

4 recordsLinked to original sources

arXiv2026

Mapping open quantum dynamics onto graphs

Graph-theoretic frameworks have been widely employed in quantum physics to address the high-dimensional complexity of quantum systems. Although open quantum dynamics incorporates system-bath coupling via numerous interacting operators, it has been formulated algebraically with a partial set of jump operators or statistically universal reservoirs, leaving the underlying connectivity structure largely unexplored. Here, we propose a universal graph-theoretic framework for Markovian quantum dynamics. The framework maps open quantum dynamics onto two uniquely defined graphs, where the quantum master equation is rigorously interpreted as the average wave characteristic of operator-valued signals across the graphs. Applying this framework to the open quantum Rabi model, we demonstrate an open-system generalization of Fock-state lattices, characterize graph-topological signatures of dissipation, and classify the weak-to-ultrastrong coupling transition. Building on these representations, graph pruning reveals the backbone of open quantum dynamics, which enables superior graph neural-network learning. Our results bridge graph theory and open quantum dynamics, achieving efficient data-driven analysis of high-dimensional complexity.

quant-ph↗

arXiv2026

Fully programmable slow light based on a spinor representation of generalized coupled-resonator-induced transparency

Electromagnetically induced transparency (EIT), arising from quantum interference in coherently driven atomic systems, has inspired a variety of photonic analogues, such as coupled-resonator-induced transparency (CRIT) built on the quantum-state modelling using resonators. Although CRIT serves as a building block for slow light in photonic integrated circuits, recent advances in topological photonics motivate a further generalization of both EIT and CRIT using gauge-field degrees of freedom. Here, we propose generalized CRIT via a spinor representation with dual-channel gauge fields, enabling fully programmable CRIT featuring dynamical spectral engineering. We generalize the traditional EIT framework by introducing a spinor representation of bright- and dark-mode resonances, yielding a unified description of design parameters through universal unitary operations. Implementing a coupled-resonator building block that accesses the entire design space through dual-channel gauge fields, we demonstrate a programmable slow-light band in a one-dimensional CRIT lattice. These results address urgent needs in optical interconnects, such as tunable delay lines, reconfigurable synchronization, and linear frequency conversion.

physics.optics↗

arXiv2024

Deep-subwavelength engineering of stealthy hyperuniformity

Light behaviours in disordered materials have been of research interest primarily at length scales beyond or comparable to the wavelength of light, because order and disorder are often believed to be almost indistinguishable in the subwavelength regime according to effective medium theory (EMT). However, it was recently demonstrated that the breakdown of EMT occurs even at deep-subwavelength scales when interface phenomena, such as the Goos-Hanchen effect, dominate light flows. Here we develop the engineering of disordered multilayers at deep-subwavelength scales to achieve angle-selective manipulation of wave localization. To examine the disorder-dependent EMT breakdown, we classify the intermediate regime of microstructural phases between deep-subwavelength crystals and uncorrelated disorder through the concept of stealthy hyperuniformity (SHU). In this classification, we devise nontrivial order-to-disorder transitions by selectively tailoring the short-range and long-range order in SHU multilayers, achieving angle-selective control of wave localization. The result paves the way to the realization of deep-subwavelength disordered metamaterials, bridging the gap between the fields of disordered photonics and metamaterials.

physics.optics↗

arXiv2018

An algorithm for the classification of twisted forms of toric varieties

Let $K/k$ be a finite Galois extension, $G=\text{Gal}(K/k)$, $Σ$ be a fan in a lattice $N$ and $X_Σ$ be an associated toric variety over $k$. It is well known that the set of $K/k$-forms of $X_Σ$ is in bijection with $H^1(G,\text{Aut}_Σ^T)$, where $\text{Aut}_Σ^T$ is an algebraic group of toric automorphisms of $X_Σ$. In this paper, we suggest an algorithm to compute $H^1(G,\text{Aut}_Σ^T)$ and find that followings can be classified via this algorithm : $K/k$-forms of all toric surfaces, $K/k$-forms of all 3-dimensional affine toric varieties with no torus factor, $K/k$-forms of all 3-dimensional quasi-projective toric varieties when $K/k$ is cyclic.

math.AG↗