Anomalous Nernst Effect Induced Terahertz Emission in a Single Ferromagnetic Film

Feng，Zheng1; Tan，Wei1; Jin，Zuanming2; Chen，Yi Jia3; Zhong，Zhangfeng4; Zhang，Liang5,6; Sun，Song1; Tang，Jin7; Jiang，Yexing2; Wu，Po Hsun3; Cheng，Jun4; Miao，Bingfeng4,8; Ding，Haifeng4,8; Wang，Dacheng1; Zhu，Yiming2; Guo，Liang5; Shin，Sunmi6; Ma，Guo Hong9; Hou，Dazhi10,11; Huang，Ssu Yen3

2023-09-13

10.1021/acs.nanolett.3c02320

Nano letters   Impact Factor & Quartile

1530-6992

Despite its important role in understanding ultrafast spin dynamics and revealing novel spin/orbit effects, the mechanism of the terahertz (THz) emission from a single ferromagnetic nanofilm upon a femtosecond laser pump still remains elusive. Recent experiments have shown exotic symmetry, which is not expected from the routinely adopted mechanism of ultrafast demagnetization. Here, by developing a bidirectional pump-THz emission spectroscopy and associated symmetry analysis method, we set a benchmark for the experimental distinction of the THz emission induced by various mechanisms. Our results unambiguously unveil a new mechanism─anomalous Nernst effect (ANE) induced THz emission due to the ultrafast temperature gradient created by a femtosecond laser. Quantitative analysis shows that the THz emission exhibits interesting thickness dependence where different mechanisms dominate at different thickness ranges. Our work not only clarifies the origin of the ferromagnetic-based THz emission but also offers a fertile platform for investigating the ultrafast optomagnetism and THz spintronics.

Anomalous Nernst effect Ferromagnet Nanofilm Spintronic Terahertz emission Ultrafast magnetism

English

NI Journal Papers

Others

MATERIALS SCIENCE

2-s2.0-85171203021

Scopus

1.Microsystem & Terahertz Research Center,CAEP,Chengdu,610200,China
2.Terahertz Technology Innovation Research Institute,Terahertz Spectrum and Imaging Technology Cooperative Innovation Center,Shanghai Key Lab of Modern Optical System,University of Shanghai for Science and Technology,200093,China
3.Department of Physics,National Taiwan University,10617,Taiwan
4.National Laboratory of Solid State Microstructures and Department of Physics,Nanjing University,Nanjing,210093,China
5.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
6.Department of Mechanical Engineering,National University of Singapore,117516,Singapore
7.School of Physics and Optoelectronics Engineering Science,Anhui University,Hefei,230601,China
8.Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing,210093,China
9.Department of Physics,Shanghai University,200444,China
10.ICQD,Hefei National Laboratory for Physical Sciences at Microscale,University of Science and Technology of China,Hefei,230026,China
11.Department of Physics,University of Science and Technology of China,Hefei,230026,China

Feng，Zheng,Tan，Wei,Jin，Zuanming,et al. Anomalous Nernst Effect Induced Terahertz Emission in a Single Ferromagnetic Film[J]. Nano letters,2023,23(17):8171-8179.

Feng，Zheng.,Tan，Wei.,Jin，Zuanming.,Chen，Yi Jia.,Zhong，Zhangfeng.,...&Huang，Ssu Yen.(2023).Anomalous Nernst Effect Induced Terahertz Emission in a Single Ferromagnetic Film.Nano letters,23(17),8171-8179.

Feng，Zheng,et al."Anomalous Nernst Effect Induced Terahertz Emission in a Single Ferromagnetic Film".Nano letters 23.17(2023):8171-8179.