No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.
Bandgap modulation in photoexcited topological insulator Bi2
via atomic displacements
H. Zhang et al., “Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface,” Nat. Phys. 5, 438 (2009).
D.-X. Qu, Y. S. Hor, J. Xiong, R. J. Cava, and N. P. Ong, “Quantum oscillations and hall anomaly of surface states in the topological insulator Bi2Te3,” Science 329, 821 (2010).
J. W. McIver, D. Hsieh, H. Steinberg, P. Jarillo-Herrero, and N. Gedik, “Control over topological insulator photocurrents with light polarization,” Nat. Nanotechnol. 7, 96 (2012).
Y. H. Wang, H. Steinberg, P. Jarillo-Herrero, and N. Gedik, “Observation of Floquet-Bloch states on the surface of a topological insulator,” Science 342, 453 (2013).
See supplementary material at http://dx.doi.org/10.1063/1.4955188
for supplementary Figure S1 which shows infrared transmittance spectra from Bi2
at temperatures of 287 K and 390 K. In Figure S2, we indicate the time constant of the decrease and recovery in the mid-infrared probe reflectance spectroscopy. Figure S3 shows the infrared-to-visible reflectivity spectrum at room temperature. Figure S4 shows that the time evolution of the electron diffraction intensity from the
planes corresponds to spot 1–6 and that the time evolution from the
planes corresponds to spots 7 and 8. Figure S5 shows the time-resolved change in the diffuse scattering background. Figure S6 shows the time-resolved electron intensity from the
diffraction plane. Figure S7 shows atomic displacements derived from the time-resolved electron diffraction. Figure S8 shows the Raman spectrum and the coherent phonon vibrations determined from the conventional near-IR pump-probe experiment. Tables S1–S7 present the atomic coordinates obtained from the time-resolved electron diffraction.[Supplementary Material]
M. Hajlaoui et al., “Tuning a Schottky barrier in a photoexcited topological insulator with transient Dirac cone electron-hole asymmetry,” Nat. Commun. 5, 3003 (2014).
J. A. Sobota et al., “Distinguishing bulk and surface electron-phonon coupling in the topological insulator Bi2Se3 using time-resolved photoemission spectroscopy,” Phys. Rev. Lett. 113, 157401 (2014).
K. Norimatsu et al., “Dynamics of all the Raman-active coherent phonons in Sb2Te3 revealed via transient reflectivity,” J. Appl. Phys. 117, 143102 (2015).
N. Fukazawa et al., “Time-resolved infrared vibrational spectroscopy of the photoinduced phase transition of Pd(dmit)2 salts having different orders of phase transition,” J. Phys. Chem. C 117, 13187 (2013).
M. Hada, K. Pichugin, and G. Sciain, “Ultrafast structural dynamics with table top femtosecond hard x-ray and electron diffraction setups,” Eur. Phys. J.: Spec. Top. 222, 1093 (2013).
Y. D. Glinka et al., “Ultrafast carrier dynamics in thin-films of the topological insulator Bi2Se3,” Appl. Phys. Lett. 103, 151903 (2013).
H. Cui, I. B. Bhat, B. O’Quinn, and R. Venkatasubramanian, “In-situ monitoring of the growth of Bi2Te3 and Sb2Te3 films and Bi2Te3-Sb2Te3 superlattice using spectroscopic ellipsometry,” J. Electron. Mater. 30, 1376 (2001).
A. Y. Morsy, S. S. Fouad, E. Hashem, and A. A. El-Shazly, “Optical properties of thermally deposited bismuth telluride in the wavelength range of 2.5–10 μm,” Acta Phys. Pol., A 80, 819 (1991).
M. Hada, K. Okimura, and J. Matsuo, “Characterization of structural dynamics of VO2 thin film on c-Al2O3 using in-air time-resolved x-ray diffraction,” Phys. Rev. B 82, 153401 (2010).
L.-M. Peng, “Quasi-dynamical electron diffraction—A kinematic type of expression for the dynamical diffracted-beam amplitudes,” Acta Crystallogr., Sect. A 56, 511 (2000).
S. Nie, X. Wang, J. Li, R. Clinite, and J. Cao, “Femtosecond electron diffraction: Direct probe of ultrafast structural dynamics in metal films,” Microsc. Res. Tech. 72, 131 (2009).
M. J. Gutmann, G. Graziano, S. Mukhopadhyay, K. Refson, and M. von Zimmerman, “Computation of diffuse scattering arising from one-phonon excitations in a neutron time-of-flight single-crystal Laue diffraction experiment,” J. Appl. Crystallogr. 48, 1122 (2015).
G. Moriena, M. Hada, G. Sciaini, J. Matsuo, and R. J. D. Miller, “Femtosecond electron diffraction: Preparation and characterization of (110)-oriented bismuth films,” J. Appl. Phys. 111, 043504 (2012).
K. Hoefer et al., “Intrinsic conduction through topological surface states of insulating Bi2Te3 epitaxial thin films,” Proc. Natl. Acad. Sci. U. S. A. 111, 14979 (2014).
P. W. Juodawlkis and S. E. Ralph, “Hole-induced transient bandgap renormalization: A mechanism for photo-induced absorption in defect-engineered semiconductors,” Appl. Phys. Lett. 76, 1722 (2000).
Article metrics loading...
The atomic and electronic dynamics in the topological insulator (TI) Bi2Te3 under strong photoexcitation were characterized with time-resolved
electron diffraction and time-resolved mid-infrared spectroscopy. Three-dimensional TIs characterized as bulk insulators with an electronic conduction surface band have shown a variety of exotic responses in terms of electronic transport when observed under conditions of applied pressure, magnetic field, or circularly polarized light. However, the atomic motions and their correlation between electronic systems in TIs under strong photoexcitation have not been explored. The artificial and transient modification of the electronic structures in TIs via photoinduced atomic motions represents a novel mechanism for providing a comparable level of bandgap control. The results of time-domain crystallography indicate that photoexcitation induces two-step atomic motions: first bismuth and then tellurium center-symmetric displacements. These atomic motions in Bi2Te3 trigger 10% bulk bandgap narrowing, which is consistent with the time-resolved mid-infrared spectroscopy results.
Full text loading...
Most read this month