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Title: Observation of exceptional points in magnonic parity-time symmetry devices
Non-Hermitian Hamiltonians may still have real eigenvalues, provided that a combined parity-time (ƤƮ) symmetry exists. The prospect of ƤƮ symmetry has been explored in several physical systems such as photonics, acoustics, and electronics. The eigenvalues in these systems undergo a transition from real to complex at exceptional points (EPs), where the ƤƮ symmetry is broken. Here, we demonstrate the existence of EP in magnonic devices composed of two coupled magnets with different magnon losses. The eigenfrequencies and damping rates change from crossing to anti-crossing at the EP when the coupling strength increases. The magnonic dispersion includes a strong “acoustic-like” mode and a weak “optic-like” mode. Moreover, upon microwave radiation, the ƤƮ magnonic devices act as magnon resonant cavity with unique response compared to conventional magnonic systems.  more » « less
Award ID(s):
1836989
PAR ID:
10192479
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Science Advances
Volume:
5
Issue:
11
ISSN:
2375-2548
Page Range / eLocation ID:
eaax9144
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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