Searcharxiv⌕ Search

arXiv subjects

Seonguk Kim

Publications and source records attributed to Seonguk Kim.

5 recordsLinked to original sources
arXiv2026

Ring Optimized M-APSK Modulation for Discrete Modulated CV-QKD

This paper proposes a multi ring M-APSK constellation optimization method for discrete-modulated continuous variable quantum key distribution. Unlike conventional APSK structures with fixed ring spacing and predefined ring probabilities, the proposed method optimizes the ring radius ratio and ring probability to improve the finite-size secret key rate. A method based on the Gram matrix is used to calculate the nonzero spectrum of the average state $\tau$, and fidelity is used to compare the optimized discrete average state with the Gaussian average state. The results show that the proposed structure extends the maximum transmission distance of 16-APSK by approximately 15% compared with the conventional binomial APSK structure. The optimization gain is larger for small size APSK constellations, where the average state has a larger structural gap from Gaussian modulation.

quant-ph↗
arXiv2022

Solutions of Gross-Pitaevskii Equation with Periodic Potential in Dimension Three

Quasi-periodic solutions of the Gross-Pitaevskii equation with a periodic potential in dimension three are studied. It is proven that there is an extensive "non-resonant" set ${\mathcal G} \subset \mathbb{R}^3$ such that for every $\vec k\in \mathcal G$ there is a solution asymptotically close to a plane wave $Ae^{i\langle{ \vec{k}, \vec{x} }\rangle}$ as $|\vec k|\to \infty $, given $A$ is sufficiently small.

math-ph↗
arXiv2018

Solutions of Gross-Pitaevskii Equation with Periodic Potential in Dimension Two

Quasi-periodic solutions of a nonlinear polyharmonic equation for the case $4l>n+1$ in $\R^n$, $n>1$, are studied. This includes Gross-Pitaevskii equation in dimension two ($l=1,n=2$). It is proven that there is an extensive "non-resonant" set ${\mathcal G}\subset \R^n$ such that for every $\vec k\in \mathcal G$ there is a solution asymptotically close to a plane wave $Ae^{i\langle{ \vec{k}, \vec{x} }\rangle}$ as $|\vec k|\to \infty $, given $A$ is sufficiently small.

math-ph↗
arXiv2017

Solutions of Nonlinear Polyharmonic Equation with Periodic Potential

Quasi-periodic solutions of a nonlinear periodic polyharmonic equation in $\R^n$, $n>1$, are studied. It is proven that there is an extensive "non-resonant" set ${\mathcal G}\subset \R^n$ such that for every $\vec k\in \mathcal G$ there is a solution asymptotically close to a plane wave $Ae^{i\langle{ \vec{k}, \vec{x} }\rangle}$ as $|\vec k|\to \infty $.

math-ph↗