arXiv subjects

Deyan Sun

Publications and source records attributed to Deyan Sun.

3 recordsLinked to original sources

arXiv2025

Mean-squared Energy Difference for Exploring Potential Energy Landscapes of Supercooled Liquids

By extending the concept of diffusion to the potential energy landscapes (PELs), we introduce the mean-squared energy difference (MSED) as a novel quantity to investigate the intrinsic properties of glass. MSED can provide a clear description of the "energy relaxation" process on a PEL. Through MSED analysis, we can obtain characteristic timescale similar to those from structure analysis, namely $\tau_\alpha^*$. We establish a connection between MSED and the properties of PELs, providing a concise and quantitative description of the PEL. We find that the roughness of the accessible PEL has changed significantly after the glass transition. And we also find that one of the PEL parameters is closely related to the Adam-Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of the glass.

cond-mat.dis-nn↗

arXiv2020

Establishing simple relationship between eigenvector and matrix elements

A simple approximate relationship between the ground-state eigenvector and the sum of matrix elements in each row has been established for real symmetric matrices with non-positive off-diagonal elements. Specifically, the $i$-th components of the ground-state eigenvector could be calculated by $(-S_i)^p+c$, where $S_i$ is the sum of elements in the $i$-th row of the matrix with $p$ and $c$ being variational parameters. The simple relationship provides a straightforward method to directly calculate the ground-state eigenvector for a matrix. Our preliminary applications to the Hubbard model and the Ising model in a transverse field show encouraging results.The simple relationship also provide the optimal initial state for other more accurate methods, such as the Lanczos method.

cond-mat.mes-hall↗

arXiv2019

A new strategy for directly calculating the minimum eigenvector of matrices without diagonalization

The diagonalization of matrices may be the top priority in the application of modern physics. In this paper, we numerically demonstrate that, for real symmetric random matrices with non-positive off-diagonal elements, a universal scaling between the eigenvector and matrix elements exists. Namely, each element of the eigenvector of ground states linearly correlates with the sum of matrix elements in the corresponding row. Although the conclusion is obtained based on the random matrices, the linear relationship still keeps for regular matrices, in which off-diagonal elements are non-positive. The relationship implies a straightforward method to directly calculate the eigenvector of ground states for a kind of matrices. The test on both Hubbard and Ising models shows that, this new method works excellently.

quant-ph↗