collaborators

7 papers

cond-mat.str-el2026

Quantum geometric localization length and localization criticality in an ideally flat Chern band

Xu-Cheng Wang, Yang Qi

We propose that the localization length in an isolated, ideally flat Chern band is set by quantum geometry. We explore the corresponding localization transition and its critical sc…

cond-mat.supr-con2026

Emergent magnetic pseudogap from phase fluctuations and hierarchy of scales in two-dimensional superconductors

Xu-Cheng Wang, Yang Qi

Preformed pairs and phase fluctuations are believed to play a vital role in predicting the charge pseudogap in the normal state of two-dimensional superconductors. In this work, we…

math.OC2026

Structure-Preserving Spectral Dynamic Programming on Compact Lie Groups

Shanqing Liu, Yang Qi

We study spectral approximations of the dynamic programming semigroup for finite-horizon optimal control on a connected compact Lie group , and of the associated first-order Ham…

math.OC2026

Tropical low-rank approximation and application to optimal control of N-body systems

Marianne Akian, Stephane Gaubert, Shanqing Liu +1

We study the approximation of the value function of deterministic optimal control problems with fixed initial state, motivated by \(N\)-body systems. In this setting, the action fu…

cond-mat.str-el2026

Fluctuating Pair Density Wave in Finite-temperature Phase Diagram of the - Hubbard Model

Qiaoyi Li, Yang Qi, Wei Li

The Hubbard model and its extensions are canonical theoretical frameworks for understanding correlated electronic states, including those in high- cuprates. Here, we use state…

cond-mat.mes-hall2026

Revealing Higher-Order Topological Bulk-boundary Correspondence in Bismuth Crystal with Spin-helical Hinge State Loop and Proximity Superconductivity

D. M. Zhao, Y. Zhong, T. Yuan +7

Topological materials are typically characterized by gapless boundary states originated from nontrivial bulk band topology, known as topological bulk-boundary correspondence. Recen…