Generalized Gauge Transformation with PT‐Symmetric Non‐Unitary Operator and Classical Correspondence of Non‐Hermitian Hamiltonian for a Periodically Driven System (Ann. Phys. 6/2022)

Gauge Transformation The front cover design is inspired by an ancient Chinese folk tale, “the Cowherd and the Vega”. The Vega was a carefree goddess, and the Cowherd was a hard-working cattle herder on the earth. They lived in two different worlds, but accidentally met and fell in love. According to the tale, they meet every year on the bridge of magpies. In the cover design, depicting the research reported by Jiu-Qing Liang and co-workers in article number 2200069, the Vega represents the Berry phase, which comes from the quantum world. The Cowherd represents the Hannay angle, which comes from classical world. The bridge of magpies is the PT-symmetric non-Hermitian. A certain connection between the Berry phase and Hannay angle is called the quantum–classical correspondence.