Recently, Dr. Wang Ran and Professor Zhang Xizheng from the School of Physics and Materials Science at Tianjin Normal University (TNU) have made significant progress in detecting quantum phase transitions in superconducting bosonic systems, proposing a novel method to probe such transitions in bosonic Kitaev systems. The research findings have been published online in Physical Review B under the title "Probing quantum phase transitions in a staggered bosonic Kitaev chain via Fock space resolved localization-delocalization transitions."

The statistical properties of bosons, which allow for macroscopic multiple occupancy of single-particle states, pose a major challenge—both analytically and numerically—for analyzing quantum phase transitions in interacting bosonic systems. This study systematically investigated the non-Hermitian core matrix of a Hermitian staggered bosonic Kitaev chain constructed using the Nambu representation. By mapping the many-body Hamiltonian to an effective tight-binding network in Fock space and introducing the layer-resolved inverse participation ratio, the research demonstrates that exceptional points correspond precisely to the transition points between localized and delocalized collective eigenstates. The results establish a framework for probing critical behavior in interacting bosonic lattices based on exceptional points, and this detection method can be directly applied to current mainstream quantum simulation platforms.

Figure: Schematic of the effective model's lattice in Fock space.

TNU is the sole institution responsible for this work. Dr. Wang Ran is the first author, and Professor Zhang Xizheng is the corresponding author. The related work was supported by the General Program and Young Scientists Fund of the National Natural Science Foundation of China (12374461, 12305026) and the Scientific Research Plan Project of Tianjin Municipal Education Commission (2024KJ060).

Article links: https://doi.org/10.1103/6lhp-8q6k

By He Jierui