geometricphasesWe discuss the basic theoretical framework for non-Hermitian quantum systems with particular emphasis on the diagonalizability of non-Hermitian Hamiltonians and their general linear GL(1,C) gauge freedom, which are relevant to the adiabatic evolution of non-Hermitian quantum systems. We...
Non-Hermitian singularities are ubiquitous in non-conservative open systems. Owing to their peculiar topology, they can remotely induce observable effects when encircled by closed trajectories in the parameter space. To date, a general formalism for describing this process beyond simple cases is still ...
Non-Abelian non-Hermitian systemNonreciprocityAdiabatic evolutionGeometric phaseIn this work, we investigate the adiabatic evolution and geometric phase in non-Abelian non-Hermitian systems. By analyzing the adiabatic condition for non-Hermitian systems exhibiting energy degeneracy, we derive the non-Abelian...
For a T -periodic non-Hermitian Hamiltonian H ( t ), we construct a class of adiabatic cyclic states of period T which are not eigenstates of the initial Hamiltonian H (0). We show that the corresponding adiabatic geometric phase angles are real and discuss their relationship with the ...
In Eq. (3), one can see both the intrinsic Berry phase in the Hermitian limit (i.e., \(\varphi _0/2\)) and the non-Hermitian-induced geometric phase. Consequently, instead of being quantized, the Berry phase in each band becomes continuously varying due to the non-Hermitian-induced ...
In the general case of an exact cyclic evolution the role of the Hamiltonian in generating the approximate cyclic states as its eigenstates is played by another parameter-dependent Hermitian operator, h̃ = h̃ ( R ). In this case, the non-degeneracy requirement applies to h̃. In ...
Non-Hermitian Parent Hamiltonian and Composite Quantum Phases | 青年科学半月谈 开始时间 2023-04-27 10:00 题目:Non-Hermitian Parent Hamiltonian and Composite Quantum Phases | 青年科学半月谈 时间:2023年4月27日(周四)10:00 报告人:Yuchen Guo Abstract: In this talk, I plan to introduce our two ...
In a non-Hermitian system, the eigenvalues are complex, and corresponding eigenstates form a non orthogonal set. One of the most interesting phenomena in non-Hermitian quantum mechanics is the presence of exceptional points (EPs) in the parameter space of physical problems. At the EP, not only...
Recently, intense research efforts have focused on exploring non-Hermitian systems with cleverly matched gain and loss, facilitating unidirectional invisibility and exotic characteristics of exceptional points3,4. Likewise, the surge in physics using topological insulators comprising non-trivial symmetry-...
Non-Hermitian photonics and topological photonics, as new research fields in optics, have attracted much attention in recent years, accompanying by a great deal of new physical concepts and novel effects emerging. The two fields are gradually crossed during the development process and the non-Hermiti...