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Related papers: Higher-order exceptional points in all-magnetic st…

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Exceptional points (EPs) in non-Hermitian photonics offer singular sensitivity enhancements but have thus far been realized almost exclusively in spatially engineered platforms with fixed geometries and limited tunability. Here we extend EP…

We investigate the existence of higher order exceptional points (EPs) in non-Hermitian systems, and show that $\mu$-fold EPs are stable in $\mu-1$ dimensions in the presence of anti-unitary symmetries that are local in parameter space, such…

Mesoscale and Nanoscale Physics · Physics 2021-10-27 Pierre Delplace , Tsuneya Yoshida , Yasuhiro Hatsugai

Exceptional point degeneracies (EPD) of linear non-Hermitian systems have been recently utilized for hypersensitive sensing. This proposal exploits the sublinear response that the degenerate frequencies experience once the system is…

Exceptional points (EPs) -- spectral singularities of non-Hermitian linear systems -- have recently attracted great interest for sensing. While initial proposals and experiments focused on enhanced sensitivities neglecting noise, subsequent…

Optics · Physics 2022-07-13 K. J. H. Peters , S. R. K. Rodriguez

Exceptional points (EPs) in non-Hermitian systems offer a remarkably strong response to weak perturbations, but the nonorthogonal nature of the corresponding eigenvectors causes noise to diverge, hindering EPs practical application. Here,…

Defective spectral degeneracy, known as exceptional point (EP), lies at the heart of various intriguing phenomena in optics, acoustics, and other nonconservative systems. Despite extensive studies in the past two decades, the…

Mesoscale and Nanoscale Physics · Physics 2023-04-13 Cui-Xian Guo , Shu Chen , Kun Ding , Haiping Hu

As an important device for detecting rotation, high sensitivity gyroscope is required for practical applications. In recent years, exceptional point (EP) shows its potential in enhancing the sensitivity of sensing in optical cavity. Here we…

Optics · Physics 2020-09-25 Xuan Mao , Guo-qing Qin , Hao Zhang , Hong Yang , Min Wang , Gui-lu Long

Geometrically confined magnetic particles due to their unique response to external magnetic fields find a variety of applications, including magnetic guidance, heat and drug delivery, magneto-mechanical actuation, and contrast enhancement.…

Motivated by the recent growing interest in the field of $\mathcal{P}\mathcal{T}$-symmetric Hamiltonian systems we theoretically study the emergency of singularities called Exceptional Points ($\textit{EP}$s) in the eigenspectrum of…

Quantum Physics · Physics 2023-08-15 Grigory A. Starkov , Mikhail V. Fistul , Ilya M. Eremin

Strong ferromagnetic interlayer exchange couplings $J$ in perpendicularly magnetized systems are becoming increasingly desirable for applications. We study whether ferromagnetic interlayer exchange couplings can be measured by a combination…

Materials Science · Physics 2016-04-22 Thibaut Devolder

The energy level degeneracies, also known as exceptional points (EPs), are crucial for comprehending emerging phenomena in materials and enabling innovative functionalities for devices. Since EPs were proposed over half a century age, only…

Quantum Physics · Physics 2025-03-12 Yang Wu , Dongfanghao Zhu , Yunhan Wang , Xing Rong , Jiangfeng Du

We derive new exceptional point (EP) conditions of the coupled microring resonators using coupled mode theory in space, a more accurate approach than the commonly used coupled mode theory in time. Transmission spectra around EPs obtained…

Optics · Physics 2024-10-24 Kunpeng Zhu , Xiaoyan Zhou , Yinxin Zhang , Zhanhua Huang , Lin Zhang

An unconventional magnet may be mapped onto a simple ferromagnet by the existence of a high-symmetry point. Knowledge of conventional ferromagnetic systems may then be carried over to provide insight into more complex orders. Here we…

Computational Physics · Physics 2021-07-28 Nihal Rao , Ke Liu , Lode Pollet

Negative-index materials (NIMs) are shown to support optical anti-parity-time (anti-PT) symmetry even when they are lossless. Here we prove the feasibility in achieving higher-order exceptional points (EPs) in loss-free waveguide arrays by…

Classical Physics · Physics 2023-04-19 Xin-Zhe Zhang , Li-Ting Wu , Ru-Zhi Luo , Jing Chen

Exceptional points of order $n$ (EP$n$s) appear in non-Hermitian systems as points where the eigenvalues and eigenvectors coalesce. They emerge if $2(n-1)$ real constraints are imposed, such that EP2s generically appear in two dimensions…

Mesoscale and Nanoscale Physics · Physics 2024-06-07 Anton Montag , Flore K. Kunst

The responsivity of perturbation sensing can be effectively enhanced by using higher-order exceptional points (HOEPs) due to their nonlinear response to frequency perturbations. However, experimental realization can be difficult due to the…

Optics · Physics 2024-12-02 Todd Darcie , J. Stewart Aitchison

Photonic topological edge states in one-dimensional dimer chains have long been thought to be robust to structural perturbations by mapping the topological Su-Schrieffer-Heeger model of a solid-state system. However, the edge states at the…

Applied Physics · Physics 2020-07-10 Zhiwei Guo , Tengzhou Zhang , Juan Song , Haitao Jiang , Hong Chen

We explore ways to use the ability to measure the populations of individual magnetic sublevels to improve the sensitivity of magnetic field measurements and measurements of atomic electric dipole moments (EDMs). When atoms are initialized…

Quantum Physics · Physics 2018-03-14 Cheng Tang , Teng Zhang , David S. Weiss

Despite extensive researches on manganites owing to widespread use in modern electronics, this class of metal oxides does not cease to surprise with its unique properties and new phenomena. Here we have studied structural and magnetic…

We report an all-lossy index-guided dual-core photonic crystal fiber (PCF) that hosts a second-order exceptional point (EP) in the systems parameter space. By appropriately selecting a parametric encirclement scheme around the EP, the…

Optics · Physics 2025-03-06 Shamba Ghosh , Arpan Roy , Bishnu P. Pal , Somnath Ghosh