Non-Hermitian superfluid–Mott-insulator transition in the one-dimensional zigzag bosonic chains

We investigated the behavior of non-Hermitian bosonic gases with Hubbard interactions in one-dimensional (1D) zigzag optical lattices through the calculation of dynamic response functions. Our findings showed the existence of a non-Hermitian quantum phase transition that is dependent on the pseudo-Hermitian symmetry. The system tends to exhibit a superfluid phase when subjected to weak dissipation. While under strong dissipation, the pseudo-Hermitian symmetry of the system is partially broken, leading to a transition toward a normal liquid phase. As the dissipation increases beyond the critical threshold, the pseudo-Hermitian symmetry is completely broken, resulting in a Mott-insulator phase. We propose an experimental setup using 1D zigzag optical lattices containing two-electron atoms to realize this system. In this paper, we emphasize the key role of non-Hermiticity in quantum phase transitions and offer a theoretical framework as well as experimental methods for understanding the behavior of dissipative quantum systems, implicating significant development of quantum devices and technologies.