scholarly journals Investigating Optical Properties of One-Dimensional Photonic Crystals Containing Semiconductor Quantum Wells

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Mahshid Mokhtarnejad ◽  
Morteza Asgari ◽  
Arash Sabatyan
Keyword(s):  
Band Structure ◽  
Quantum Wells ◽  
Pump Pulse ◽  
Probe Pulse ◽  
Stark Effect ◽  
Optical Switch ◽  
Incident Angle ◽  
One Dimensional ◽  
Maximum Reflectivity ◽  
The One

This study examined MQWs made of InGaAs/GaAs, InAlAs/InP, and InGaAs/InP in terms of their band structure and reflectivity. We also demonstrated that the reflectivity of MQWs under normal incident was at maximum, while both using a strong pump and changing incident angle reduced it. Reflectivity of the structure for a weak probe pulse depends on polarization, intensity of the pump pulse, and delay between the probe pulse and the pump pulse. So this system can be used as an ultrafast all-optical switch which is inspected by the transfer matrix method. After studying the band structure of the one-dimensional photonic crystal, the optical stark effect (OSE) was considered on it. Due to the OSE on virtual exciton levels, the switching time can be in the order of picoseconds. Moreover, it is demonstrated that, by introducing errors in width of barrier and well as well as by inserting defect, the reflectivity is reduced. Thus, by employing the mechanism of stark effect MQWs band-gaps can be easily controlled which is useful in designing MWQ based optical switches and filters. By comparing the results, we observe that the reflectivity of MWQ containing 200 periods of InAlAs/InP quantum wells shows the maximum reflectivity of 96%.

The Resonant Modes in One-Dimensional Photonic Crystal Parallel Quantum Wells Composed of Negative Index Materials

2013 ◽  
Vol 401-403 ◽  
pp. 748-753
Author(s):  
Xu Yang Xiao ◽  
Run Ping Chen ◽  
Zheng Fu Cheng
Keyword(s):  
Photonic Crystal ◽  
Dispersion Relation ◽  
Quantum Wells ◽  
Incident Angle ◽  
One Dimensional ◽  
Dimensional Photonic Crystal ◽  
Resonant Modes ◽  
The One ◽  
Scattering Matrix Method ◽  
Photonic Band

We propose the one-dimensional photonic crystal quantum well structure composed of two negative metamaterials, the features of which are investigated with scattering matrix method. With this method, the transmittance, reflectance and dispersion relation of electromagnetic wave propagation in photonic crystal are obtained. Moreover, the photonic band structure is given by dispersion relation. For photonic crystal parallel wells the sandwich structure (MpNqMp) and four PCs structure (MpNqMpNq), the resonant modes exist in the photonic band gaps. The number of resonant modes is varied by changing the period number of the constituent photonic crystals. Meanwhile, the resonant modes is not sensitive to the incident angle increasing, only shift slowly to lower frequency region. Moreover, the resonant modes can be act as multiple ultra-narrow bandwidth filters.

scholarly journals Quantum conductance staircase of holes in silicon nanosandwiches

2019 ◽  
Vol 20 (2) ◽  
pp. 81-98
Author(s):  
N. T. Bagraev ◽  
L. E. Klyachkin ◽  
A. M. Malyarenko ◽  
V. S. Khromov
Keyword(s):  
Kinetic Energy ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Energy Gap ◽  
Point Contact ◽  
Quantum Conductance ◽  
One Dimensional ◽  
Drastic Increase ◽  
Quantum Point ◽  
The One

The results of studying the quantum conductance staircase of holes in one−dimensional channels obtained by the split−gate method inside silicon nanosandwiches that are the ultra−narrow quantum well confined by the delta barriers heavily doped with boron on the n−type Si (100) surface are reported. Since the silicon quantum wells studied are ultra−narrow (~2 nm) and confined by the delta barriers that consist of the negative−U dipole boron centers, the quantized conductance of one−dimensional channels is observed at relatively high temperatures (T > 77 K). Further, the current−voltage characteristic of the quantum conductance staircase is studied in relation to the kinetic energy of holes and their sheet density in the quantum wells. The results show that the quantum conductance staircase of holes in p−Si quantum wires is caused by independent contributions of the one−dimensional (1D) subbands of the heavy and light holes; these contributions manifest themselves in the study of square−section quantum wires in the doubling of the quantum−step height (G0 = 4e2/h), except for the first step (G0 = 2e2/h) due to the absence of degeneracy of the lower 1D subband. An analysis of the heights of the first and second quantum steps indicates that there is a spontaneous spin polarization of the heavy and light holes, which emphasizes the very important role of exchange interaction in the processes of 1D transport of individual charge carriers. In addition, the field−related inhibition of the quantum conductance staircase is demonstrated in the situation when the energy of the field−induced heating of the carriers become comparable to the energy gap between the 1D subbands. The use of the split−gate method made it possible to detect the effect of a drastic increase in the height of the quantum conductance steps when the kinetic energy of holes is increased; this effect is most profound for quantum wires of finite length, which are not described under conditions of a quantum point contact. In the concluding section of this paper we present the findings for the quantum conductance staircase of holes that is caused by the edge channels in the silicon nanosandwiches prepared within frameworks of the Hall. This longitudinal quantum conductance staircase, Gxx, is revealed by the voltage applied to the Hall contacts, Vxy, to a maximum of 4e2/h. In addition to the standard plateau, 2e2/h, the variations of the Vxy voltage appear to exhibit the fractional forms of the quantum conductance staircase with the plateaus and steps that bring into correlation respectively with the odd and even fractional values.

Preparation and Optical Properties of One-Dimensional Ag/SiOx Photonic Crystal

2014 ◽  
Vol 576 ◽  
pp. 27-31
Author(s):  
Gai Mei Zhang ◽  
Can Wang ◽  
Yan Jun Guo ◽  
Wang Wei ◽  
Xiao Xiang Song
Keyword(s):  
Photonic Crystal ◽  
Band Gap ◽  
Electromagnetic Waves ◽  
Photonic Band Gap ◽  
Incident Angle ◽  
One Dimensional ◽  
The One ◽  
Photonic Band ◽  
Gap Width ◽  
Band Gap Width

The photonic crystal has the property that electromagnetic waves with interval of frequency in photonic band gap (PBG) can not be propagated, so it has important applying and researching value. The traditional one-dimensional photonic crystal is with narrow band gap width, and the reflection within the band is small, especially the band gap is sensitive to the incident angle and the polarization of light. A new photonic band gap (PBG) structure, metallodielectric photonic crystal by inserting metal film in the medium can overcomes the shortcomings mentioned above. The one-dimensional Ag/SiOx photonic crystal was prepared, and theoretical and experimental researches were developed. The results show that photonic band gap appears gradually and the band gap width increase with increasing of period of repeating thickness. With the thickness of Ag film increasing, the band gap width increases, but the starting wavelength of the photonic band gap keeps unchanged. With thickness of SiOx film increasing, the band gap width of photonic band gap also increases, but it is not obvious and starting wavelength increases.

Electronic Structure of One-Dimensional Biradical Molecular Chain

2014 ◽  
Vol 1605 ◽  
Author(s):  
H. Koike ◽  
K. Ogawa ◽  
T. Kubo ◽  
K. Uchida ◽  
M. Chikamatsu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Photoelectron Spectroscopy ◽  
Organic Molecules ◽  
Molecular Chain ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Deposition Method ◽  
One Dimensional ◽  
The One

ABSTRACTWe investigated electronic structure of one-dimensional biradical molecular chain which is constructed by exploiting the covalency between organic molecules of a diphenyl derivative of s-indacenodiphenalene (Ph2-IDPL). To control the crystallinity, we used gas deposition method. Ultraviolet photoelectron spectroscopy (UPS) revealed developed band structure with wide dispersion of the one-dimensional biradical molecular chain.

Uniaxial Stress-Effect on the One-Dimensional Band Structure of [Pt (en)2][Pt (en)2Cl2](ClO4)4(en=ethylenediamine)

1987 ◽  
Vol 56 (3) ◽  
pp. 1197-1202 ◽  
Author(s):  
Masatoshi Tanaka ◽  
Wakahiko Kaneko ◽  
Susumu Kurita ◽  
Akio Yamada ◽  
Hirohito Fukutani
Keyword(s):  
Band Structure ◽  
Uniaxial Stress ◽  
Stress Effect ◽  
One Dimensional ◽  
The One

Temperature-Triggered Reversible Dielectric and Nonlinear Optical Switch Based on the One-Dimensional Organic–Inorganic Hybrid Phase Transition Compound [C6H11NH3]2CdCl4

2014 ◽  
Vol 53 (20) ◽  
pp. 11146-11151 ◽  
Author(s):  
Wei-Qiang Liao ◽  
Heng-Yun Ye ◽  
Da-Wei Fu ◽  
Peng-Fei Li ◽  
Li-Zhuang Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Nonlinear Optical ◽  
Optical Switch ◽  
Inorganic Hybrid ◽  
One Dimensional ◽  
The One
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