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Author Xiao, H.; Zhang, Z.; Xu, W.; Wang, Q.; Xiao, Y.; Ding, L.; Huang, J.; Li, H.; He, B.; Peeters, F.M.
Title Terahertz optoelectronic properties of synthetic single crystal diamond Type A1 Journal article
Year 2023 Publication Diamond and related materials Abbreviated Journal
Volume 139 Issue Pages 110266-110268
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A systematic investigation is undertaken for studying the optoelectronic properties of single crystal diamond (SCD) grown by microwave plasma chemical vapor deposition (MPCVD). It is indicated that, without intentional doping and surface treatment during the sample growth, the terahertz (THz) optical conduction in SCD is mainly affected by surface H-terminations, -OH-, O- and N-based functional groups. By using THz time-domain spectroscopy (TDS), we measure the transmittance, the complex dielectric constant and optical conductivity σ(ω) of SCD. We find that SCD does not show typical semiconductor characteristics in THz regime, where σ(ω) cannot be described rightly by the conventional Drude formula. Via fitting the real and imaginary parts of σ(ω) to the Drude-Smith formula, the ratio of the average carrier density to the effective electron mass γ = ne/m*, the electronic relaxation time τ and the electronic backscattering or localization factor can be determined optically. The temperature dependence of these parameters is examined. From the temperature dependence of γ, a metallic to semiconductor transition is observed at about T = 10 K. The temperature dependence of τ is mainly induced by electron coupling with acoustic-phonons and there is a significant effect of photon-induced electron backscattering or localization in SCD. This work demonstrates that THz TDS is a powerful technique in studying SCD which contains H-, N- and O-based bonds and has low electron density and high dc resistivity. The results obtained from this study can benefit us to gain an in-depth understanding of SCD and may provide new guidance for the application of SCD as electronic, optical and optoelectronic materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-08-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-9635 ISBN Additional Links UA library record
Impact Factor 4.1 Times cited (down) Open Access
Notes Approved Most recent IF: 4.1; 2023 IF: 2.561
Call Number UA @ admin @ c:irua:200920 Serial 9103
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Author Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V.
Title Floquet engineering of axion and high-Chern number phases in a topological insulator under illumination Type A1 Journal article
Year 2024 Publication SciPost Physics Core Abbreviated Journal
Volume 7 Issue 7 Pages 024-16
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Quantum anomalous Hall, high-Chern number, and axion phases in topological insulators are characterized by its Chern invariant C (respectively, C = 1, integer C > 1, and C = 0 with half-quantized Hall conductance of opposite signs on top and bottom surfaces). They are of recent interest because of novel fundamental physics and prospective applications, but identifying and controlling these phases has been challenging in practice. Here we show that these states can be created and switched between in thin films of Bi2Se3 by Floquet engineering, using irradiation by circularly polarized light. We present the calculated phase diagrams of encountered topological phases in Bi2Se3, as a function of wavelength and amplitude of light, as well as sample thickness, after properly taking into account the penetration depth of light and the variation of the gap in the surface states. These findings open pathways towards energy-efficient optoelectronics, advanced sensing, quantum information processing and metrology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001217885300001 Publication Date 2024-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited (down) Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:205972 Serial 9151
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