scholarly journals Surface plasmon on graphene at finite T

2016 ◽  
Vol 30 (19) ◽  
pp. 1650120 ◽  
Author(s):  
M. Bordag ◽  
I. G. Pirozhenko
Keyword(s):  
Chemical Potential ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Dispersion Function ◽  
Polarization Tensor ◽  
Electronic Excitations ◽  
Zero Temperature ◽  
Mass Gap ◽  
Influence Of Temperature On ◽  
Momentum Region

Using the recently developed polarization tensor in [Formula: see text] dimensions for the electronic excitations of graphene, we investigate the influence of temperature on the surface plasmons on graphene. We consider nonzero mass gap, but zero chemical potential. Plasmons may exist for both polarizations, transverse electric (TE) and transverse magnetic (TM), of the electromagnetic field. For TE, the momentum region, where the dispersion function is real, appears bounded from below, whereas for TM it is bounded from above. We discuss the similarities of these features with those found previously in the case with nonzero chemical potential, but zero temperature.

scholarly journals Interband plasmon polaritons in magnetized charge-neutral graphene

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
T. M. Slipchenko ◽  
J.-M. Poumirol ◽  
A. B. Kuzmenko ◽  
A. Yu. Nikitin ◽  
L. Martín-Moreno
Keyword(s):  
Transverse Electric ◽  
Near Field ◽  
Single Layer ◽  
Transverse Magnetic ◽  
Zero Temperature ◽  
Absorption Bands ◽  
Charge Carrier Dynamics ◽  
Quantum Phenomena ◽  
Plasmon Polaritons ◽  
The Magnetic Field

AbstractStudying the collective excitations in charge neutral graphene (CNG) has recently attracted a great interest because of unusual mechanisms of the charge carrier dynamics. The latter can play a crucial role for formation of recently observed in twisted bilayer CNG graphene plasmon polaritons (GPPs) associated with the interband transitions between the flat electronic bands. Besides, GPPs in CNG can be a tool providing insights into various quantum phenomena in CNG via optical experiments. However, the properties of interband GPPs in CNG are not known, even in the simplest configurations. Here, we show that magnetically-biased single-layer CNG can support interband GPPs of both transverse magnetic and transverse electric polarizations (particularly, at zero temperature). GPPs exist inside the absorption bands originating from the electronic transitions between Landau levels and are tunable by the magnetic field. We place our study into the context of potential near-field and far-field optical experiments.

Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators

2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Author(s):  
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Dual Band ◽  
Single Peak ◽  
Wide Angle ◽  
Surface Current Density

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

scholarly journals More on complex Sachdev-Ye-Kitaev eternal wormholes

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Pengfei Zhang
Keyword(s):  
Black Hole ◽  
Ground State ◽  
Effective Action ◽  
Chemical Potential ◽  
Specific Charge ◽  
Zero Temperature ◽  
Small Coupling ◽  
Chemical Potentials ◽  
Quench Dynamics ◽  
Two Sides

Abstract In this work, we study a generalization of the coupled Sachdev-Ye-Kitaev (SYK) model with U(1) charge conservations. The model contains two copies of the complex SYK model at different chemical potentials, coupled by a direct hopping term. In the zero-temperature and small coupling limit with small averaged chemical potential, the ground state is an eternal wormhole connecting two sides, with a specific charge Q = 0, which is equivalent to a thermofield double state. We derive the conformal Green’s functions and determine corresponding IR parameters. At higher chemical potential, the system transit into the black hole phase. We further derive the Schwarzian effective action and study its quench dynamics. Finally, we compare numerical results with the analytical predictions.

Magnetic plasmons induced in a dielectric-metal heterostructure by optical magnetism

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shulei Li ◽  
Lidan Zhou ◽  
Mingcheng Panmai ◽  
Jin Xiang ◽  
Sheng Lan
Keyword(s):  
Transverse Electric ◽  
Incidence Angle ◽  
High Sensitivity ◽  
Critical Value ◽  
Transverse Magnetic ◽  
Quality Factors ◽  
Light Spectrum ◽  
Optical Resonances ◽  
Scattering Spectra ◽  
Plasmon Polaritons

Abstract We investigate numerically and experimentally the optical properties of the transverse electric (TE) waves supported by a dielectric-metal heterostructure. They are considered as the counterparts of the surface plasmon polaritons (i.e., the transverse magnetic (TM) waves) which have been extensively studied in the last several decades. We show that TE waves with resonant wavelengths in the visible light spectrum can be excited in a dielectric-metal heterostructure when the optical thickness of the dielectric layer exceeds a critical value. We reveal that the electric and magnetic field distributions for the TE waves are spatially separated, leading to higher quality factors or narrow linewidths as compared with the TM waves. We calculate the thickness, refractive index and incidence angle dispersion relations for the TE waves supported by a dielectric-metal heterostructure. In experiments, we observe optical resonances with linewidths as narrow as ∼10 nm in the reflection or scattering spectra of the TE waves excited in a Si3N4/Ag heterostructure. Finally, we demonstrate the applications of the lowest-order TE wave excited in a Si3N4/Ag heterostructure in optical display with good chromaticity and optical sensing with high sensitivity.

Sensitivity characterization of polarization operating by embedded reflective grating

2021 ◽  
Author(s):  
Jiaman Hong ◽  
Bo Wang ◽  
Xiaoqing Zhu ◽  
Zhichao Xiong ◽  
Yusen Huang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Electric Field Intensity ◽  
High Efficiency ◽  
Transverse Electric ◽  
Tolerance Analysis ◽  
Transverse Magnetic ◽  
Infrared Band ◽  
Element Analysis ◽  
Field Intensity Distribution

In this paper, a novel embedded reflective grating (ERG) is presented to realize bi-function polarization operating at infrared band by finite element analysis (FEM). For transverse electric (TE) polarization, a two-port output (0th and −2nd orders) with an efficiency of more than 47% and excellent uniformity can be obtained. For transverse magnetic (TM) polarization, a high efficiency output of 94.72% can be achieved at the −2th order. The results of the analysis of the electric field intensity distribution, angular and wavelength bandwidths further demonstrate the advantages of the proposed grating. In addition, the tolerance analysis of period and duty cycle prove the feasibility of the grating in practical production.

scholarly journals Quad-Band Plasmonic Perfect Absorber for Visible Light with a Patchwork of Silicon Nanorod Resonators

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1954 ◽  
Author(s):  
Can Cao ◽  
Yongzhi Cheng
Keyword(s):  
Visible Light ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Localized Surface Plasmon ◽  
Perfect Absorber ◽  
Absorption Properties ◽  
Perfect Absorption ◽  
Potential Applications ◽  
Polarization Insensitive ◽  
Band Absorption

In this paper, a plasmonic perfect absorber (PPA) based on a silicon nanorod resonator (SNRR) for visible light is proposed and investigated numerically. The proposed PPA is only a two-layer nanostructure consisting of a SNRR periodic array and metal substrate. The perfect absorption mainly originates from excitation of the localized surface plasmon resonance (LSPR) mode in the SNRR structure. The absorption properties of this design can be adjusted by varying the radius (r) and height (h) of the SNRR structure. What is more, the stronger quad-band absorption can be achieved by combing four different radius of the SNRR in one period as a super unit-cell. Numerical simulation indicates that the designed quad-band PPA can achieve the absorbance of 99.99%, 99.8%, 99.8%, and 92.2% at 433.5 THz, 456 THz, 482 THz, and 504.5 THz, respectively. Further simulations show that the proposed PPA is polarization-insensitive for both transverse electric (TE) and transverse magnetic (TM) modes. The proposed PPA can be a desirable candidate for some potential applications in detecting, sensing, and visible spectroscopy.

Tc of intermediate coupling superconductors with a variable electronic density of states (EDOS)

1983 ◽  
Vol 61 (2) ◽  
pp. 212-219
Author(s):  
M. Ashraf ◽  
J. P. Carbotte
Keyword(s):  
Density Of States ◽  
Chemical Potential ◽  
Present Calculation ◽  
Zero Temperature ◽  
Intermediate Coupling ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Dimensionless Ratio ◽  
Arbitrary Position ◽  
Analytical Expressions

Using the model of Leavens and Carbotte for intermediate coupling superconductors, we have derived and evaluated analytical expressions for the critical temperature Tc, and the zero temperature gap Δ0 of those superconductors with a variable electronic density of states (EDOS). EDOS is given by a Lorentzian peak superimposed on a constant background with the chemical potential falling at some arbitrary position within the peak. The most significant modifications occur for a narrow Lorentzian with the peak close to the Fermi level. The value of the dimensionless ratio 2Δ0/kBTc remains close to the Bardeen–Cooper–Schrieffer (BCS) value of 3.53. Also, the present calculation compares very favourably with a previous exact calculation.

A MODEL STUDY OF QUARK NUMBER SUSCEPTIBILITY AT FINITE CHEMICAL POTENTIAL AND ZERO TEMPERATURE

2009 ◽  
Vol 24 (12) ◽  
pp. 2241-2251 ◽  
Author(s):  
YAN-BIN ZHANG ◽  
FENG-YAO HOU ◽  
YU JIANG ◽  
WEI-MIN SUN ◽  
HONG-SHI ZONG
Keyword(s):  
General Result ◽  
Chemical Potential ◽  
Direct Method ◽  
Quark Propagator ◽  
Zero Temperature ◽  
Quark Number ◽  
Model Study ◽  
Analytic Expression ◽  
A Direct Method ◽  
Quark Number Susceptibility

In this paper, we try to provide a direct method for calculating quark number susceptibility at finite chemical potential and zero temperature. In our approach, quark number susceptibility is totally determined by G[μ](p) (the dressed quark propagator at finite chemical potential μ). By applying the general result given in Phys. Rev. C71, 015205 (2005), G[μ](p) is calculated from the model quark propagator proposed in Phys. Rev. D67, 054019 (2003). From this the full analytic expression of quark number susceptibility at finite μ and zero T is obtained.

scholarly journals Silicon Waveguide Optical Isolator with Directly Bonded Magneto-Optical Garnet

2019 ◽  
Vol 9 (3) ◽  
pp. 609 ◽  
Author(s):  
Yuya Shoji ◽  
Tetsuya Mizumoto
Keyword(s):  
Phase Shift ◽  
Transverse Electric ◽  
Core Layer ◽  
Transverse Magnetic ◽  
Silicon Waveguide ◽  
Optical Isolation ◽  
Tm Mode ◽  
Mode Converters ◽  
Optical Isolators ◽  
Thin Interlayer

Silicon waveguide optical isolators were fabricated by direct bonding of magneto-optical (MO) garnet. The technique allowed efficient MO phase shift owing to the use of single-crystalline garnet and negligibly thin interlayer on the silicon core layer. A Mach–Zehnder interferometer (MZI) provided optical isolation utilizing the MO phase shift. High isolation, wide bandwidth, and temperature-insensitive operations had been demonstrated by tailoring the MZI design. Also, transverse electric (TE)–transverse magnetic (TM) mode converters were integrated to control operating polarization. In this paper, we reviewed these progresses on silicon waveguide optical isolators.

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