Efficient Generation and Arbitrary Manipulation of Chiral Terahertz Waves Emitted from Bi2Te3–Fe Heterostructures

Advanced Photonics Research

Yutong Li¹  Li Wang¹  Chun Wang¹  Chen Ouyang¹  Gaoshuai Wei¹  Weisheng Zhao²  Hangtian Wang²  Tianxiao Nie²  Xinhou Chen³  Xiaojun Wu³  Jungang Miao³ 

[1] Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China;Fert Beijing Institute, BDBC, and School of Microelectronics Beihang University Beijing 100191 China;School of Electronic and Information Engineering Beihang University Beijing 100191 China;

关键词: photogalvanic effects;    polarization manipulation;    spin-to-charge conversion;    terahertz radiation;    topological insulators;   

DOI  :  10.1002/adpr.202000099

来源: DOAJ

【 摘 要 】

Polarization arbitrary manipulated terahertz (THz) pulses with a prescribed amplitude temporal evolution and deposited electric‐field vectors can promote many disruptive technologies and enable enormous applications in polarization‐sensitive THz spectroscopy and imaging, ultrafast THz optospintronics, information encryption, and space exploration. However, the severe shortage of dynamically tunable THz polarization devices has impeded the proliferation of THz science and technology. Herein, a method of efficient generation and arbitrary manipulation of chiral THz waves in the topological insulator (TI)–iron (Fe) heterostructures through delicately engineering the linear photogalvanic effect (LPGE) and spin‐to‐charge conversion (SCC) effect induced by femtosecond laser pulses is proposed and demonstrated. Utilizing the intrinsic merits of optical‐controlled LPGE and magnetic field direction‐adjusted SCC effect, the TI–Fe can radiate chiral THz waves with arbitrarily tailored chirality and ellipticity. To verify the capability of such a novel chiral THz source, helical substructure associates THz circular dichroism spectroscopy is implemented on several (bio)materials, exemplified by the beetle exoskeletons. Furthermore, ultrafast switching between two THz chirality states can be realized by a double‐pulse excitation scheme. Such versatile chiral THz emitters with high efficiency and easy integration may have some disruptive applications.

【 授权许可】

Unknown