Chiral and non-chiral swift mode conversion near an exception point with dynamic adiabaticity engineering
arXiv:2304.12912 · doi:10.1103/PhysRevB.110.064308
Abstract
The eigenvalue of a non-Hermitian Hamiltonian often forms a self-intersecting Riemann surface, leading to a unique mode conversion phenomenon when the Hamiltonian evolves along certain loop paths around an exceptional point (EP). However, two fundamental problems exist with the conventional scheme of EP encircling: the speed of mode conversion is restricted by the adiabatic requirement, and the chirality cannot be freely controlled. Here, we introduce a method which dynamically engineers the adiabaticity in the evolution of non-Hermitian Hamiltonians that allows for both chiral and non-chiral mode conversion on the same path. Our method is based on quantifying and controlling the instantaneous adiabaticity, allowing for non-uniform evolution throughout the entire path. We apply our method into the microwave waveguide system and by optimizing the distributed adiabaticity along the evolution loop, we achieve the same quality of mode conversion as conventional quasi-adiabatic evolution in only one-fourth of the time. Our approach provides a comprehensive and universal solution to address the speed and chirality challenges associated with EP encircling. It also facilitates the dynamic manipulation and regulation of non-adiabatic processes, thereby accelerating the operation and allowing for a selection among various mode conversion patterns.
References in corpus (18)
- Unidirectional Invisibility induced by PT-Symmetric Periodic Structures
- Non-Hermitian Physics
- Symmetry and Topology in Non-Hermitian Physics
- Dynamically encircling exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity
- Shortcuts to adiabaticity: concepts, methods, and applications
- Efficiency at maximum power: An analytically solvable model for stochastic heat engines
- The emergence, coalescence and topological properties of multiple exceptional points and their experimental realization
- Acoustic non-Hermitian skin effect from twisted winding topology
- Dynamically encircling exceptional points: Exact evolution and polarization state conversion
- Dynamically encircling an exceptional point in anti-PT-symmetric systems: asymmetric mode switching for symmetry-broken states
- Introduction to the Pontryagin Maximum Principle for Quantum Optimal Control
- Dynamically encircling exceptional points: in situ control of encircling loops and the role of the starting point
- Dynamically encircling an exceptional point in a real quantum system
- Observation of Chiral State Transfer Without Encircling an Exceptional Point
- Chiral state-conversion without encircling an exceptional point
- Controlling the speed and trajectory of evolution with counterdiabatic driving
- Enhancement of quantum heat engine by encircling a Liouvillian exceptional point
- Pontryagin-Optimal Control of a non-Hermitian Qubit