Generation and manipulation of chiral terahertz waves in the three-dimensional topological insulator Bi2Te3

Abstract. Arbitrary manipulation of broadband terahertz waves with flexible polarization shaping at the source has great potential in expanding numerous applications, such as imaging, information encryption, and all-optical coherent control of terahertz nonlinear phenomena. Topological insulators featuring unique spin-momentum–locked surface state have already exhibited very promising prospects in terahertz emission, detection, and modulation, which may lay a foundation for future on-chip topological insulator-based terahertz systems. However, polarization-shaped terahertz emitters based on topological insulators with an arbitrarily manipulated temporal evolution of the amplitude and the electric-field vector direction have not yet been explored. We systematically investigated the terahertz radiation from topological insulator Bi2Te3 nanofilms driven by femtosecond laser pulses and successfully realized the generation of efficient chiral terahertz waves with controllable chirality, ellipticity, and principal axis. The convenient engineering of the chiral terahertz waves was interpreted by a photogalvanic effect (PGE)-induced photocurrent, while the linearly polarized terahertz waves originated from linear PGE-induced shift currents. Our work not only provides further understanding of femtosecond coherent control of ultrafast spin currents but also describes an effective way to generate spin-polarized terahertz waves at the source.

[1]  Julien Perruisseau-Carrier,et al.  Near optimal graphene terahertz non-reciprocal isolator , 2016, Nature Communications.

[2]  J. Hebling,et al.  Generation, tuning, and shaping of narrow-band, picosecond THz pulses by two-beam excitation. , 2004, Optics express.

[3]  Po-Tsun Liu,et al.  Thickness-dependent magnetotransport properties and terahertz response of topological insulator Bi2Te3 thin films , 2017 .

[4]  Yun-Shik Lee,et al.  Generation of arbitrary terahertz wave forms in fanned-out periodically poled lithium niobate , 2006 .

[5]  Cunjun Ruan,et al.  Broadband Spintronic Terahertz Emitter with Magnetic‐Field Manipulated Polarizations , 2019, Advanced Optical Materials.

[6]  Masahiro Sato,et al.  High-harmonic generation by electric polarization, spin current, and magnetization , 2019 .

[7]  D. Grischkowsky,et al.  MEASUREMENTS OF THE THZ ABSORPTION AND DISPERSION OF ZNTE AND THEIR RELEVANCE TO THE ELECTRO-OPTIC DETECTION OF THZ RADIATION , 1999 .

[8]  Jae Ho Jeon,et al.  Helicity-dependent photocurrent in a B i 2 S e 3 thin film probed by terahertz emission spectroscopy , 2016 .

[9]  Giuseppe Vallone,et al.  Simple quantum key distribution with qubit-based synchronization and a self-compensating polarization encoder , 2019, Optica.

[10]  Theodore B. Norris,et al.  Terahertz Circular Dichroism Spectroscopy of Biomaterials Enabled by Kirigami Polarization Modulators , 2019, bioRxiv.

[11]  L. E. Golub,et al.  Photon drag effect in (Bi1−xSbx)2Te3 three-dimensional topological insulators , 2015, 1512.07078.

[12]  K. Nelson,et al.  Resonant and nonresonant control over matter and light by intense terahertz transients , 2013, Nature Photonics.

[13]  Yi Wang,et al.  Ultrafast Spin‐to‐Charge Conversion at the Surface of Topological Insulator Thin Films , 2018, Advanced materials.

[14]  Chih-Wei Luo,et al.  Helicity-dependent terahertz emission spectroscopy of topological insulator S b 2 T e 3 thin films , 2017 .

[15]  J Kampmeier,et al.  Room-temperature high-frequency transport of dirac fermions in epitaxially grown Sb2Te3- and Bi2Te3-based topological insulators. , 2014, Physical review letters.

[16]  P. Jarillo-Herrero,et al.  Control over topological insulator photocurrents with light polarization. , 2011, Nature nanotechnology.

[17]  Y. Gao,et al.  Chiral terahertz wave emission from the Weyl semimetal TaAs , 2019, Nature Communications.

[18]  Shuying Cheng,et al.  Helicity-dependent photocurrent of the top and bottom Dirac surface states of epitaxial thin films of three-dimensional topological insulators Sb2Te3 , 2019 .

[19]  Eunsoon Oh,et al.  Tunable terahertz generation using femtosecond pulse shaping , 2002 .

[20]  R. Laflamme,et al.  Robust quantum communication using a polarization-entangled photon pair. , 2004, Physical review letters.

[21]  Nitin Samarth,et al.  Helicity dependent photocurrent in electrically gated (Bi1−xSbx)2Te3 thin films , 2017, Nature Communications.

[22]  D. R. Chowdhury,et al.  Terahertz Metamaterials for Linear Polarization Conversion and Anomalous Refraction , 2013, Science.

[23]  Gregor Mussler,et al.  Ultrafast photocurrents at the surface of the three-dimensional topological insulator Bi2Se3 , 2015, Nature Communications.

[24]  S. D. Ganichev,et al.  Spin-galvanic effect , 2002, Nature.

[25]  Kosuke Yoshioka,et al.  Terahertz polarization pulse shaping with arbitrary field control , 2013, Nature Photonics.

[26]  Alexandra Junck,et al.  Theory of Photocurrents in Topological Insulators , 2015 .

[27]  Jie Zhang,et al.  Manipulation of polarizations for broadband terahertz waves emitted from laser plasma filaments , 2018, Nature Photonics.

[28]  Xi-Cheng Zhang,et al.  Preference of subpicosecond laser pulses for terahertz wave generation from liquids , 2020 .

[29]  Xiang Zhang,et al.  Photoinduced handedness switching in terahertz chiral metamolecules , 2012, Nature Communications.

[30]  Xi Dai,et al.  Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface , 2009 .

[31]  Th. Rasing,et al.  Terahertz Optomagnetism: Nonlinear THz Excitation of GHz Spin Waves in Antiferromagnetic FeBO_{3}. , 2019, Physical review letters.

[32]  Yan Zhang,et al.  Efficient manipulations of circularly polarized terahertz waves with transmissive metasurfaces , 2019, Light: Science & Applications.

[33]  Weisheng Zhao,et al.  Nonlinear terahertz emission in the three-dimensional topological insulator Bi2Te3 by terahertz emission spectroscopy , 2019, Applied Physics Letters.

[34]  P. Freitas,et al.  Femtosecond control of electric currents in metallic ferromagnetic heterostructures. , 2015, Nature nanotechnology.

[35]  Mengji Chen,et al.  Anisotropic Picosecond Spin-Photocurrent from Weyl Semimetal WTe2. , 2020, ACS nano.

[36]  Kosuke Yoshioka,et al.  The vectorial control of magnetization by light , 2011, Nature communications.

[37]  Cunjun Ruan,et al.  Generation and manipulation of chiral broadband terahertz waves from cascade spintronic terahertz emitters , 2019 .