papers

Publications (20)

cond-mat.mtrl-sci2021

Gate-tunable artificial nucleus in graphene

Mykola Telychko, Keian Noori, Hillol Biswas +12

We report an atomically-precise integration of individual nitrogen (N) dopant as an in-plane artificial nucleus in a graphene device by atomic implantation to probe its gate-tunabl…

math.NA2021

A symmetric fractional-order reduction method for direct nonuniform approximations of semilinear diffusion-wave equations

Pin Lyu, Seakweng Vong

We introduce a symmetric fractional-order reduction (SFOR) method to construct numerical algorithms on general nonuniform temporal meshes for semilinear fractional diffusion-wave e…

cond-mat.mes-hall2023

Atomically-precise Vacancy-assembled Quantum Antidots

Hanyan Fang, Harshitra Mahalingam, Xinzhe Li +16

Patterning antidots ("voids") into well-defined antidot lattices creates an intriguing class of artificial structures for the periodic modulation of 2D electron systems, leading to…

math.NA2020

A fast implicit difference scheme for solving the generalized time-space fractional diffusion equations with variable coefficients

Xian-Ming Gu, Ting-Zhu Huang, Yong-Liang Zhao +2

In this paper, we first propose an unconditionally stable implicit difference scheme for solving generalized time-space fractional diffusion equations (GTSFDEs) with variable coeff…

cond-mat.mes-hall2011

Size effect of Ruderman-Kittel-Kasuya-Yosida interaction mediated by electrons in nanoribbons

Shuo Mi, Shuo-Hong Yuan, Pin Lyu

We calculated the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the magnetic impurities mediated by electrons in nanoribbons. It was shown that the RKKY interaction is s…

math.NA2023

Discrete gradient structure of a second-order variable-step method for nonlinear integro-differential models

Hong-lin Liao, Nan Liu, Pin Lyu

The discrete gradient structure and the positive definiteness of discrete fractional integrals or derivatives are fundamental to the numerical stability in long-time simulation of…

math.NA2017

A linearized second-order scheme for nonlinear time fractional Klein-Gordon type equations

Pin Lyu, Seakweng Vong

We consider difference schemes for nonlinear time fractional Klein-Gordon type equations in this paper. A linearized scheme is proposed to solve the problem. As a result, iterative…

cs.SE2025

GitTaskBench: A Benchmark for Code Agents Solving Real-World Tasks Through Code Repository Leveraging

Ziyi Ni, Huacan Wang, Shuo Zhang +15

Beyond scratch coding, exploiting large-scale code repositories (e.g., GitHub) for practical tasks is vital in real-world software development, yet current benchmarks rarely evalua…

cs.SE2025

RepoMaster: Autonomous Exploration and Understanding of GitHub Repositories for Complex Task Solving

Huacan Wang, Ziyi Ni, Shuo Zhang +11

The ultimate goal of code agents is to solve complex tasks autonomously. Although large language models (LLMs) have made substantial progress in code generation, real-world tasks t…

math.NA2021

Second-order and nonuniform time-stepping schemes for time fractional evolution equations with time-space dependent coefficients

Pin Lyu, Seakweng Vong

The numerical analysis of time fractional evolution equations with the second-order elliptic operator including general time-space dependent variable coefficients is challenging, e…

math.NA2019

A fast linearized finite difference method for the nonlinear multi-term time-fractional wave equation

Pin Lyu, Yuxiang Liang, Zhibo Wang

In this paper, we study a fast and linearized finite difference method to solve the nonlinear time-fractional wave equation with multi fractional orders. We first propose a discret…

math.NA2019

An efficient second-order convergent scheme for one-side space fractional diffusion equations with variable coefficients

Xue-lei Lin, Pin Lyu, Michael K. Ng +2

In this paper, a second order finite difference scheme is investigated for time-dependent one-side space fractional diffusion equations with variable coefficients. The existing sch…

cond-mat.mtrl-sci2021

Electronic Self-passivation of Single Vacancy in Black Phosphorus via a Controlled Ionization

Hanyan Fang, Aurelio Gallardo, Dikshant Dulal +11

We report that mono-elemental black phosphorus presents a new electronic self-passivation scheme of single vacancy (SV). By means of low-temperature scanning tunneling microscopy a…

math.NA2017

On a second order scheme for space fractional diffusion equations with variable coefficients

Seakweng Vong, Pin Lyu

We study a second order scheme for spatial fractional differential equations with variable coefficients. Previous results mainly concentrate on equations with diffusion coefficient…

cond-mat.str-el2001

Tunneling magnetoresistance in diluted magnetic semiconductor tunnel junctions

Pin Lyu, Kyungsun Moon

Using the spin-polarized tunneling model and taking into account the basic physics of ferromagnetic semiconductors, we study the temperature dependence of the tunneling magnetoresi…

cs.LG2026

SDO: Structure-Aware Data Organization for Efficient LLM Post-Training

Jinliang Gao, Ning Yang, Hai Wang +2

The paper introduces SDO, a plug‑and‑play framework that dynamically organizes training data for large language model post‑training by using exposure‑driven feedback and K‑nearest‑…

#large language model fine-tuning#data organization#exposure balancing#knn batching
cond-mat.mes-hall2025

Visualization of Strain-Induced Landau Levels in a Graphene - Black Phosphorus Heterostructure

Thi-Hai-Yen Vu, Pin Lyu, Na Hyun Jo +8

Strain-induced pseudo magnetic fields offer the possibility of realizing zero magnetic field Quantum Hall effect in graphene, possibly up to room temperature, representing a promis…

cond-mat.mes-hall2022

Giant gate-tunable renormalization of spin-correlated flat-band states and bandgap in a 2D magnetic insulator

Pin Lyu, Joachim Sødequist, Xiaoyu Sheng +8

Emergent quantum phenomena in two-dimensional van der Waal (vdW) magnets are largely governed by the interplay between the exchange and Coulomb interactions. The ability to tune th…

math.NA2021

A high-order and fast scheme with variable time steps for the time-fractional Black-Scholes equation

Kerui Song, Pin Lyu

In this paper, a high-order and fast numerical method is investigated for the time-fractional Black-Scholes equation. In order to deal with the typical weak initial singularities o…

cond-mat.mes-hall2002

Ferromagnetism in diluted magnetic semiconductor quantum dot arrays embedded in semiconductors

Pin Lyu, Kyungsun Moon

We present an Anderson-type model Hamiltonian with exchange coupling between the localized spins and the confined holes in the quantum dots to study the ferromagnetism in diluted m…