Higher-order exceptional points in ferromagnetic trilayers

被引：36

作者：

Yu, Tianlin ^{[1
]}

Yang, Huanhuan ^{[1
]}

Song, Lingling ^{[1
]}

Yan, Peng ^{[1
]}

Cao, Yunshan ^{[1
]}

机构：

[1] Univ Elect Sci & Technol China, Sch Elect Sci & Engn, Chengdu 610054, Peoples R China

来源：

PHYSICAL REVIEW B | 2020年 / 101卷 / 14期

基金：

中国国家自然科学基金;

关键词：

PARITY-TIME SYMMETRY; ENHANCED SENSITIVITY;

D O I：

10.1103/PhysRevB.101.144414

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Magnetometers with exceptional sensitivity are highly demanded in solving a variety of physical and engineering problems, such as measuring Earth's weak magnetic fields and prospecting mineral deposits and geological structures. It has been shown that the non-Hermitian degeneracy at exceptional points (EPs) can provide a new route for that purpose, because of the nonlinear response to external perturbations. One recent work [H. Yang et al. Phys. Rev. Lett. 121, 197201 (2018)] has made the first step to realize the second-order magnonic EP in ferromagnetic bilayers respecting the parity-time symmetry. In this paper, we generalize the idea to higher-order cases by considering ferromagnetic trilayers consisting of a gain, a neutral, and a (balanced-)loss layer. We observe both second- and third-order magnonic EPs by tuning the interlayer coupling strength, the external magnetic field, and the gain-loss parameter. We show that the magnetic sensitivity can be enhanced by three orders of magnitude comparing to the conventional magnetic tunneling junction-based sensors. Our results pave the way for studying high-order EPs in purely magnetic system and for designing magnetic sensors with ultrahigh sensitivity.

引用

页数：8

共 53 条

[11] Magnetic tunnel junction sensors with pTesla sensitivity [J].

Cardoso, S. ;

Leitao, D. C. ;

Gameiro, L. ;

Cardoso, F. ;

Ferreira, R. ;

Paz, E. ;

Freitas, P. P. .

MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, 2014, 20 (4-5) :793-802

[12]

Caruso M.J., 1997, READINGS, V72, P15, DOI DOI 10.4271/970602

[13] Generalized parity-time symmetry condition for enhanced sensor telemetry [J].

Chen, Pai-Yen ;

Sakhdari, Maryam ;

Hajizadegan, Mehdi ;

Cui, Qingsong ;

Cheng, Mark Ming-Cheng ;

El-Ganainy, Ramy ;

Alu, Andrea .

NATURE ELECTRONICS, 2018, 1 (05) :297-304

[14] Exceptional points enhance sensing in an optical microcavity [J].

Chen, Weijian ;

Ozdemir, Sahin Kaya ;

Zhao, Guangming ;

Wiersig, Jan ;

Yang, Lan .

NATURE, 2017, 548 (7666) :192-+

[15] Observation of an anti-PT-symmetric exceptional point and energy-difference conserving dynamics in electrical circuit resonators [J].

Choi, Youngsun ;

Hahn, Choloong ;

Yoon, Jae Woong ;

Song, Seok Ho .

NATURE COMMUNICATIONS, 2018, 9

[16] Brillouin light scattering studies of confined spin waves: linear and nonlinear confinement [J].

Demokritov, SO ;

Hillebrands, B ;

Slavin, AN .

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 2001, 348 (06) :441-489

[17] Nanowire spin torque oscillator driven by spin orbit torques [J].

Duan, Zheng ;

Smith, Andrew ;

Yang, Liu ;

Youngblood, Brian ;

Lindner, Juergen ;

Demidov, Vladislav E. ;

Demokritov, Sergej O. ;

Krivorotov, Ilya N. .

NATURE COMMUNICATIONS, 2014, 5

[18] Interlayer magnetic coupling interactions of two ferromagnetic layers by spin polarized tunneling [J].

Faure-Vincent, J ;

Tiusan, C ;

Bellouard, C ;

Popova, E ;

Hehn, M ;

Montaigne, F ;

Schuhl, A .

PHYSICAL REVIEW LETTERS, 2002, 89 (10)

[19] Single-mode laser by parity-time symmetry breaking [J].

Feng, Liang ;

Wong, Zi Jing ;

Ma, Ren-Min ;

Wang, Yuan ;

Zhang, Xiang .

SCIENCE, 2014, 346 (6212) :972-975

[20] Wide-range tuning of interfacial exchange coupling between ferromagnetic Au/Co and ferrimagneticTb/Fe(Co) multilayers [J].

Frackowiak, Lukasz ;

Kuswik, Piotr ;

Urbaniak, Maciej ;

Chaves-O'Flynn, Gabriel David ;

Stobiecki, Feliks .

SCIENTIFIC REPORTS, 2018, 8

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