Anisotropic Photonic Band Gap Research Articles

Geometric phase for a two-level system in photonic band gab crystal

In this work, we investigate the geometric phase (GP) for a qubit system coupled to its own anisotropic and isotropic photonic band gap (PBG) crystal environment without Born or Markovian approximation. The qubit frequency affects the GP of the qubit directly through the effect of the PBG environment. The results show the deviation of the GP depends on the detuning parameter and this deviation will be large for relatively large detuning of atom frequency inside the gap with respect to the photonic band edge. Whereas for detunings outside the gap, the GP of the qubit changes abruptly to zero, exhibiting collapse phenomenon of the GP. Moreover, we find that the GP in the isotropic PBG photonic crystal is more robust than that in the anisotropic PBG under the same condition. Finally, we explore the relationship between the variation of the GP and population in terms of the physical parameters.

Quantum speedup in structured environments

In this paper, the behavior of the quantum speed up with detuning for an open two-level system embedded in a reservoir at zero temperature within the Janes-Cummings model is studied. We consider two examples of spectral densities in the framework of non-Markovian environments: a high-Q cavity is slightly off-resonant with the transition frequency of the qubit and a two-level system coupled to an anisotropic photonic band gap crystal environment without Markovian or Born approximation. Generally, it is found that there exist a sudden transition from no speedup to speedup at certain critical detuning value, and the physical parameters do not affect the decoherence process for long driving times. Interestingly, we find that the control of the speed of the quantum evolution can be benefit from the combination of the detuning and spectral width density in the first case, while the acceleration of the quantum evolution occurs as the qubit transition frequency is detuned inside the gap for the anisotropic dispersion model. Finally, we clarify how the excited populations and non-Markovianity can be influenced by the detuning to realize the quantum speed limit.

Spontaneous emission from a microwave-driven four-level atom in an anisotropic photonic crystal**Project supported by the National Natural Science Foundation of China (Grant Nos. 11447232, 11204367, 11447157, and 11305020).

The spontaneous emission from a microwave-driven four-level atom embedded in an anisotropic photonic crystal is studied. Due to the modified density of state (DOS) in the anisotropic photonic band gap (PBG) and the coherent control induced by the coupling fields, spontaneous emission can be significantly enhanced when the position of the spontaneous emission peak gets close to the band gap edge. As a result of the closed-loop interaction between the fields and the atom, the spontaneous emission depends on the dynamically induced Autler–Townes splitting and its position relative to the PBG. Interesting phenomena, such as spectral-line suppression, enhancement and narrowing, and fluorescence quenching, appear in the spontaneous emission spectra, which are modulated by amplitudes and phases of the coherently driven fields and the effect of PBG. This theoretical study can provide us with more efficient methods to manipulate the atomic spontaneous emission.

Analysis of magneto-optical properties for three-dimensional photonic crystals in high-symmetry arrangement doped by metamaterials and uniaxial materials

Abstract In this paper, we use a modified plane wave expansion (PWE) method to investigate the properties of photonic band gaps (PBGs) for the extraordinary mode in the three-dimensional (3D) photonic crystals (PCs) which are composed of the anisotropic dielectric (the uniaxial materials) spheres immersed in the homogeneous metamaterials (epsilon-negative materials) background with high-symmetry (body-centered-cubic) lattices, as the magneto-optical Voigt effects are considered. The equations for calculating the PBGs in the first irreducible Brillouin zone are theoretically derived. It is numerically illustrated that the anisotropic PBGs and two flattened band regions can be achieved. The influences of the ordinary-refractive index, extraordinary-refractive index, filling factor of dielectric spheres, electronic plasma frequency and cyclotron frequency on the magneto-optical properties of such 3D PCs also are studied in detail, respectively, and some corresponding physical explanations are given. The numerical results demonstrate that the anisotropy can open partial band gaps in the proposed PCs, and the complete PBGs can be obtained compared with the conventional PCs only containing the isotropic material with similar structures. The bandwidths of PBGs can be tuned by introducing the epsilon-negative materials into such PCs containing the uniaxial materials. The anisotropic PBGs can be manipulated by the parameters as mentioned above. As the proposed PCs with high-symmetry lattices, the complete PBGs can be obtained by introducing the uniaxial materials.

The creation of quantum correlation and entropic uncertainty relation in photonic crystals

We investigate the dynamic creation of quantum correlation and entropic uncertainty relation (EUR) in a system of two non-interacting qubits, which are initially prepared in a classically correlated state and subject to the independent radiation in an isotropic or anisotropic photonic bandgap (PBG) crystal environment. It is shown that the detuning condition and environmental structure play a crucial role in controlling the emergence of geometric quantum discord (GQD) and one-norm GQD. In addition, the remarkable similarities and differences for quantum correlation in two PBG environments are also analyzed in detail. Finally, we explore the time evolution of EUR in our model under the influence of PBG environment and present some interesting results.

Protecting the precision of estimation in a photonic crystal

The quantum Fisher information (QFI) of a two-level atom in an anisotropic and isotropic photonic band-gap (PBG) crystal has been studied without Born or Markovian approximation. We show that the precision of the parameter estimation for the two-level atom in the photonic crystal is greatly different from that of a two-level atom in vacuum or that subjected to the usual non-Markovian reservoir. The phenomenon shows that the QFI, namely, the precision of estimation, changes dramatically with the environment structure. The results also show that, for PBG materials, environmentally high values of QFI trapping can be achieved and thus prevention of QFI sudden drop occurs, which greatly enhances the coherence and increases the precision of estimation. Moreover, the QFI in the isotropic PBG is more easily preserved than that of the anisotropic PBG under the same condition. These features make the atom system in PBG materials a good candidate for implementation of different schemes of quantum optics and information with high precision.

Study on the magneto-optical Faraday effects in the properties of anisotropic photonic band gaps and surface plasmon modes for the three-dimensional magnetized photonic crystals as the mixed polarized waves considered

In this paper, the magneto-optical Faraday effects in the properties of anisotropic photonic band gaps (PBGs) and surface plasmon modes for the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with body-centered cubic lattices are theoretically studied based on the modified plane wave expansion (PWE) method, in which the homogeneous Te (tellurium) spheres are immersed in the homogeneous magnetized plasma background, as the mixed polarized waves are considered. A more general case is investigated, and the anisotropic PBGs are not only for the left- and right-circular polarized waves but also for the mixed polarized waves. The equations for computing those anisotropic PBGs for all of the electromagnetic waves in such 3D MPPCs are theoretically deduced. Theoretical simulations show that the anisotropic PBGs and a flatbands region can be observed. Compared to the similar 3D MPPCs containing the isotropic dielectric or uniaxial material spheres, the largest PBG can be obtained as the extraordinary axis of inserted uniaxial material is along the Г-H symmetry line. The larger PBGs can also be achieved compared to the conventional PBGs for the right-circular polarized wave as the mixed polarized waves are considered. The interesting properties of surface plasmon modes can also be found, which are the upper edge of flatbands region cannot be tuned by the filling factor but almost can be linearly increased with increasing the plasma frequency and plasma cyclotron frequency, respectively. The effects of the filling factor, plasma frequency, and plasma cyclotron frequency (the external magnetic field) on the anisotropic PBGs are also investigated in detail. Theoretical simulations also show that such PBGs can be manipulated by the parameters as mentioned above.

Investigation on the magneto-optical Voigt effects in surface plasmon modes and anisotropic photonic band gap in the three-dimensional magnetized plasma photonic crystals as the mixed polarized modes considered

In this paper, the magneto-optical Voigt effects in surface plasmon modes and anisotropic photonic band gaps (PBGs) of the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic lattices are theoretically investigated based on the modified plane wave expansion (PWE) method, which are the homogeneous Te (tellurium) spheres immersed in the homogeneous magnetized plasma background, as the mixed polarized modes are considered. The more general condition is considered, and the anisotropic PBGs are not only for the extraordinary and ordinary modes but also for mixed polarized modes. The equations for computing such anisotropic PBGs are theoretically deduced. Theoretical simulations show that the anisotropic PBGs and a flatbands region can be observed in the dispersive curve. Compared to the similar 3D MPPCs containing the isotropic dielectric or uniaxial material spheres, the larger PBGs can be obtained as the extraordinary axis of the inserted uniaxial material is along the Г–H symmetry line although the region of flatbands is also different. However, the relative bandwidths of PBGs for such two cases are almost the same. The interesting properties of surface plasmon modes can also be found, which are that the upper edge of flatbands region cannot be tuned by the filling factor but can almost linearly increase on increasing the plasma frequency and plasma cyclotron frequency (the external magnetic field), respectively. The effects of the filling factor, plasma frequency and plasma cyclotron frequency on the anisotropic PBGs are investigated in detail, respectively. Theoretical calculations also show that such PBGs can be manipulated by the parameters as mentioned above.

Study on the anisotropic photonic band gaps in three-dimensional tunable photonic crystals containing the epsilon-negative materials and uniaxial materials

In this paper, the properties of anisotropic photonic band gaps (PBGs) for three-dimensional (3D) photonic crystals (PCs) composed of the anisotropic positive-index materials (the uniaxial materials) and the epsilon-negative (ENG) materials with body-centered-cubic (bcc) lattices are theoretically studied by a modified plane wave expansion (PWE) method, which are the uniaxial materials spheres inserted in the epsilon-negative materials background. The anisotropic photonic band gaps (PBGs) and one flatbands region can be achieved in first irreducible Brillouin zone. The influences of the ordinary-refractive index, extraordinary-refractive index, filling factor, the electronic plasma frequency, the dielectric constant of ENG materials and the damping factor on the properties of anisotropic PBGs for such 3D PCs are studied in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in such 3D PCs with bcc lattices composed of the ENG materials and uniaxial materials, and the complete PBGs can be obtained compared to the conventional 3D PCs containing the isotropic materials. The calculated results also show that the anisotropic PBGs can be manipulated by the parameters as mentioned above except for the damping factor. Introducing the uniaxial materials into 3D PCs containing the ENG materials can obtain the larger complete PBGs as such 3D PCs with high symmetry, and also provides a way to design the tunable devices.

The right circular polarized waves in the three-dimensional anisotropic dispersive photonic crystals consisting of the magnetized plasma and uniaxial material as the Faraday effects considered

In this paper, the properties of the right circular polarized (RCP) waves in the three-dimensional (3D) dispersive photonic crystals (PCs) consisting of the magnetized plasma and uniaxial material with face-centered-cubic (fcc) lattices are theoretically investigated by the plane wave expansion method, which the homogeneous anisotropic dielectric spheres (the uniaxial material) immersed in the magnetized plasma background, as the Faraday effects of magnetized plasma are considered (the incidence electromagnetic wave vector is parallel to the external magnetic field at any time). The equations for calculating the anisotropic photonic band gaps (PBGs) for the RCP waves in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBGs and a flatbands region can be obtained. The effects of the ordinary-refractive index, extraordinary-refractive index, anisotropic dielectric filling factor, plasma frequency, and plasma cyclotron frequency (the external magnetic field) on the properties of first two anisotropic PBGs for the RCP waves are investigated in detail, respectively. The numerical results show that the anisotropy can open partial band gaps in fcc lattices at U and W points, and the complete PBGs for the RCP waves can be achieved compared to the conventional 3D dispersive PCs composed of the magnetized plasma and isotropic material. It is also shown that the first two anisotropic PBGs can be tuned by those parameters as mentioned above. Those PBGs can be enlarged by introducing the uniaxial material into such 3D PCs as the Faraday effects are considered.

Investigating anisotropic photonic band gaps in three-dimensional plasma photonic crystals with simple-cubic lattices doped by the uniaxial material

In this paper, the properties of photonic band gaps (PBGs) for three-dimensional plasma photonic crystals (PPCs) composed of anisotropic dielectric (the uniaxial material) spheres in homogeneous unmagnetized plasma background with simple-cubic (sc) lattices are theoretically investigated by the plane wave expansion method. The equations for calculating the anisotropic PBGs in the first irreducible Brillouin zone are theoretically deduced. The influences of the ordinary-refractive index, extraordinary-refractive index, filling factor, and plasma frequency on the characteristics of anisotropic PBGs for the three-dimensional PPCs are studied in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in sc lattices and the complete PBGs can be found compared to the conventional three-dimensional PPCs doped by the isotropic material. It also is shown that the anisotropic PBGs can be manipulated by the ordinary-refractive index, extrordinary-refractive index, filling factor, and plasma frequency, respectively. Introducing the uniaxial material into three-dimensional plasma-dielectric photonic crystals can enlarge the PBGs and also provide a way to obtain the complete PBGs as the three-dimensional PPCs with high symmetry.

The anisotropic photonic band gaps in three-dimensional photonic crystals with high-symmetry lattices composed of metamaterials and uniaxial materials

In this paper, the properties of anisotropic photonic band gaps (PBGs) for three-dimensional (3D) photonic crystals (PCs) composed of tellurium (Te) spheres (the uniaxial materials) in homogeneous single-negative metamaterials (epsilon-negative materials) background with high-symmetry (simple-cubic) lattices are theoretically investigated based on the plane wave expansion method. The equations for calculating the anisotropic PBGs in the first irreducible Brillouin zone are theoretically deduced. The influences of the ordinary-refractive index, extraordinary-refractive index, filling factor of dielectric, the electronic plasma frequency, the dielectric constant of epsilon-negative materials on the anisotropic PBGs are also studied in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in simple-cubic lattices and the complete PBGs also can be achieved compared to such 3D PCs doped by the conventional isotropic materials. It also is shown that the anisotropic PBGs can be manipulated by the parameters as mentioned above. Introducing the uniaxial materials into 3D dielectric-epsilon-negative materials PCs can enlarge the PBGs, and also provide a way to obtain the complete PBGs as such kind of 3D PCs with high-symmetry lattices.

Investigation of anisotropic photonic band gaps in three-dimensional magnetized plasma photonic crystals containing the uniaxial material

In this paper, the dispersive properties of three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) composed of anisotropic dielectric (the uniaxial material) spheres immersed in homogeneous magnetized plasma background with face-centered-cubic (fcc) lattices are theoretically investigated by the plane wave expansion method, as the Voigt effects of magnetized plasma are considered. The equations for calculating the anisotropic photonic band gaps (PBGs) in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBGs and two flatbands regions can be obtained. The effects of the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency, and external magnetic field on the dispersive properties of the 3D MPPCs are investigated in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in 3D MPPCs with fcc lattices and the complete PBGs can be found compared to the conventional 3D MPPCs doped by the isotropic material. The bandwidths of PBGs can be tuned by introducing the magnetized plasma into 3D PCs containing the uniaxial material. It is also shown that the anisotropic PBGs can be manipulated by the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency, and external magnetic field, respectively. The locations of flatbands regions cannot be manipulated by any parameters except for the plasma frequency and external magnetic field. Introducing the uniaxial material can obtain the complete PBGs as the 3D MPPCs with high symmetry and also provides a way to design the tunable devices.

Investigation of Faraday effects in photonic band gap for tunable three-dimensional magnetized plasma photonic crystals containing the anisotropic material in diamond arrangement

In this paper, the properties of photonic band gaps (PBGs) for three-dimensional (3-D) magnetized plasma photonic crystals (MPPCs) composed of homogeneous magnetized plasma spheres immersed in the anisotropic dielectric (the uniaxial material) background with diamond lattices are theoretically studied by the plane wave expansion method, as the Faraday effects of magnetized plasma are considered. The equations for calculating the anisotropic PBGs in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBG and one flatbands region can be achieved. The effects of the ordinary-refractive index, extraordinary-refractive index, plasma filling factor, plasma frequency, and the external magnetic field on the characteristics of first anisotropic PBG are studied in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in diamond lattices, and the complete PBG can be obtained compared to the conventional 3-D MPPCs doped by the isotropic material (the relative bandwidth of PBG is increased by 0.1108). The bandwidth of PBG also can be enlarged by introduced the magnetized plasma into 3-D PCs containing the uniaxial material, and the relative bandwidth of PBG is increased by 0.0266. It also is shown that the first anisotropic PBG can be manipulated by the ordinary-refractive index, extraordinary-refractive index, plasma filling factor, plasma frequency, and the external magnetic field, respectively. The PBG can be enlarged by introducing the uniaxial material into 3-D MPPCs as the Faraday effects are considered. It also provides a way to enlarge the complete PBG for the 3-D MPPCs.

The Voigt effects in the anisotropic photonic band gaps of three-dimensional magnetized plasma photonic crystals doped by the uniaxial material

In this paper, the properties of photonic band gaps (PBGs) for three-dimensional magnetized plasma photonic crystals (MPPCs) composed of anisotropic dielectric (the uniaxial material) spheres immersed in homogeneous magnetized plasma background with simple-cubic lattices are theoretically investigated by the plane wave expansion (PWE) method, as the Voigt effects of magnetized plasma are considered. The equations for calculating the anisotropic PBGs in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBGs and two flatband regions can be obtained. The effects of the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency and plasma cyclotron frequency on the characteristics of anisotropic PBGs for the three-dimensional MPPCs are studied in detail and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in simple-cubic lattices and the complete PBGs can be found compared to the conventional three-dimensional MPPCs doped by the isotropic material. The bandwidths of PBGs can be enlarged by introducing the magnetized plasma into three-dimensional PCs containing the uniaxial material. It is also shown that the anisotropic PBGs can be manipulated by the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency and plasma cyclotron frequency. The locations of flatband regions cannot be tuned by any parameters except for the plasma frequency and plasma cyclotron frequency. Introducing the uniaxial material in three-dimensional magnetized plasma-dielectric photonic crystals can enlarge the PBGs and also provide a way to obtain the complete PBGs as the three-dimensional MPPCs with high symmetry.

PROPERTIES OF ANISOTROPIC PHOTONIC BAND GAPS IN THREE-DIMENSIONAL PLASMA PHOTONIC CRYSTALS CONTAINING THE UNIAXIAL MATERIAL WITH DIFFERENT LATTICES

In this paper, the properties of anisotropic photonic band gaps (PBGs) in three-dimensional (3D) nomagnetized plasma photonic crystals (PPCs) composed of anisotropic dielectric (the uniaxial material) spheres immersed in uniform nomagnetized plasma background with various lattices including the diamond, face-centered- cubic (fcc), body-centered-cubic (bcc) and simple-cubic (sc) lattices, are theoretically investigated by the plane wave expansion (PWE) method. The equations for calculating the anisotropic PBGs in the flrst irreducible Brillouin zone are theoretically deduced. The anisotropic PBGs and a ∞atbands region can be obtained as the uniaxial material introduced into 3D PPCs. The PPCs with diamond lattices consisting of isotropic dielectric have the larger PBGs compared to PPCs doped by the uniaxial material since its low-symmetry structure. Furthermore, the PPCs with fcc, bcc, sc lattices will not exhibit a complete PBG unless the uniaxial material is introduced. The in∞uences of the ordinary-refractive index, extraordinary-refractive index, fllling factor and plasma frequency external magnetic fleld on the properties of anisotropic PBGs for 3D PPCs with fcc, bcc, sc lattices are investigated in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in 3D PPCs with fcc, bcc, sc lattices, and the complete PBGs can be obtained compared to 3D PPCs doped by the conventional isotropic dielectric. It also is shown that

Microfluidic generation of magnetoresponsive Janus photonic crystal particles

Janus particles with features of an anisotropic photonic band gap (PBG) structure and magnetic property have been achieved by phase separation and self-assembly of nanoparticles in microfluidic droplets. The resultant particles enable optical encoding and magnetically controllable motion, making them excellent functional encoded particles in biomedical applications.

Controllable atom–photon entanglement near a 3D anisotropic photonic band edge

The coherent control of the entanglement between a three-level atom located within a three-dimensional (3D) anisotropic photonic band gap (PBG) material, with one transition frequency near the edge of the PBG, and its radiation field is demonstrated. As a result of quantum interference and photon localization, the entanglement can be decreased or increased depending on the relative phase between the control laser coupling, the two upper levels and the pump laser pulse used to create an excited state of the atom in the form of a coherent superposition of the two upper levels. Unlike the free-space case, the steady-state entanglement is strongly dependent on the externally prescribed initial conditions. This non-zero steady-state entanglement is achieved by virtue of the localization of light in the vicinity of the emitting atom.

Applications of Modular RBF/MLP Neural Networks in the Modeling of Microstrip Photonic Bandgap Structures

This paper presents a Radial Basis Function/Multilayer Perceptron (RBF/MLP) modular neural network, training with the Resilient Backpropagation (Rprop) algorithm which has been used for nonlinear device modeling in microwave band. The proposed modular con- flguration employs three or more neural networks, each one with a hidden layer of neurons, and aim to take advantage of the MLP and RBF networks speciflc characteristics to improve learning aspects, such as: ability to learn, speed of training and learning with consistency, or generalization. Simulations through the proposed neural network models for microstrip line with anisotropic PBG (Photonic Bandgap) structure and a metallic enclosure microstrip with PBG gave responses in good agreement with accurate results (measured or simulated) available in the literature.

Multilayer Planar Resonators with Superconductive Patch on PBG Substrate

The rectangular discretized multilayer microstrip resonators, analyzed using the full wave TTL | Transverse Transmission Line method in the spectral domain, jointly with the moment method are presented. The homogenization theory is used to calculate the equivalent permittivity for the s and p polarizations of the structure composed of PBG (Photonic Band Gap) material. Numerical results of the resonance frequency for the rectangular multilayer, on isotropic and anisotropic PBG material substrate resonators are presented. DOI: 10.2529/PIERS060908155123 The microstrip antennas have received more attention due to the characteristics and advantages comparison with the conventional antennas. These antennas present small volume, reduced weight, planar conflguration, compatibility with integrated hybrid circuits and the possibility of acting with dual frequency (1). They can be used in several systems, such as: radars, wireless, mobile telephony and communication by satellites. However, they present disadvantages with relationship to the narrow band, losses due to the low gain and losses by irradiation due to the surface waves. These disadvantages can be eliminated, by using a screening to avoid losses by irradiation (2) and antennas with PBG substrate (Photonic Bandgap) (3). Some techniques to increase the band width are used among the: thicker substrate (4), multilayer antennas or stacked patches (5,6). Antennas with dielectric multilayer have advantages, such as, the ∞exibility in the operation frequency band, a smaller physical size, etc. The PBG materials are a new type of periodic substrates structure in which the propagation in certain bands of frequencies is prohibited (7). In this work the rectangular multilayer resonators on PBG substrate are analyzed, as illustrated in the Fig. 1.