Femtosecond laser-induced crystallization of amorphous Sb{sub 2}Te{sub 3} film and coherent phonon spectroscopy characterization and optical injection of electron spins

Journal Article · Thu Sep 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3633228· OSTI ID:22036713

Simian, Li ^[1]; Huan, Huang; Yang, Wang; Yiqun, Wu; Fuxi, Gan ^[2]; Weiling, Zhu; Wenfang, Wang; Ke, Chen; Daoxin, Yao; Tianshu, Lai ^[1]

---

1. State Key Laboratory of Optoelectronic Materials and Technology, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)
2. Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

A femtosecond laser-irradiated crystallizing technique is tried to convert amorphous Sb{sub 2}Te{sub 3} film into crystalline film. Sensitive coherent phonon spectroscopy (CPS) is used to monitor the crystallization of amorphous Sb{sub 2}Te{sub 3} film at the original irradiation site. The CPS reveals that the vibration strength of two phonon modes that correspond to the characteristic phonon modes (A{sub 1g}{sup 1} and E{sub g}) of crystalline Sb{sub 2}Te{sub 3} enhances with increasing laser irradiation fluence (LIF), showing the rise of the degree of crystallization with LIF and that femtosecond laser irradiation is a good post-treatment technique. Time-resolved circularly polarized pump-probe spectroscopy is used to investigate electron spin relaxation dynamics of the laser-induced crystallized Sb{sub 2}Te{sub 3} film. Spin relaxation process indeed is observed, confirming the theoretical predictions on the validity of spin-dependent optical transition selection rule and the feasibility of transient spin-grating-based optical detection scheme of spin-plasmon collective modes in Sb{sub 2}Te{sub 3}-like topological insulators.

• OSTI ID: 22036713
• Journal Information: Journal of Applied Physics, Vol. 110, Issue 5; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ANTIMONY TELLURIDES
CRYSTALLIZATION
ELECTRONS
FILMS
IRRADIATION
LASER RADIATION
LIGHT TRANSMISSION
LITHIUM FLUORIDES
PHONONS
PLASMONS
RELAXATION
SELECTION RULES
SPECTROSCOPY
SPIN
TIME RESOLUTION
TRANSIENTS