Chu-Hui Fan | Searcharxiv

arXiv2026

Flexible Control of Temporal Reflection and Refraction via Joint Parameter Modulation

Achieving the flexible control of wave propagation is a central goal in the design of optical devices. In this work, our analytical results and numerical simulations show that in both the two-legged model and SSH model, joint modulation of coupling strengths and phases enables independent control of the probability partition and the propagation opening angles in the space-time map. We hope these results could provide a theoretical foundation for the design of programmable time-modulated optical devices.

quant-ph↗

arXiv2013

Quantum discord and quantum phase transition in spin-1/2 frustrated Heisenberg chain

By using the concept of the quantum discord (QD), we study the spin-1/2 antiferromagnetic Heisenberg chain with next-nearest-neighbor interaction. Due to the SU(2) symmetry and $Z_{2}$ symmetry in this system, we obtain the analytical result of the QD and its geometric measure (GMQD), which is determined by the two-site correlators. For the 4-site and 6-site cases, the connection between GMQD (QD) and the eigenenergies was revealed. From the analytical and numerical results, we find GMQD (QD) is an effective tool in detecting both the first-order and the infinite-order quantum-phase-transition points for the finite-size systems. Moreover, by using the entanglement excitation energy and a universal frustration measure we consider the frustration properties of the system and find a nonlinear dependence of the GMQD on the frustration.

quant-ph↗