Edge States of a Periodic Chain with Four-Band Energy Spectrum

During 2002–2003 the number of IR-identified counterparts to the Anomalous X-ray Pulsars (AXPs) has grown to four (4U 0142+61, IE 2259+586, IE 1048.1−5937 and RXS J170849−400910) out of the six objects (plus two candidates) known in this class. More importantly, some new common characteristics have been identified, such as IR variability, IR flattening in the broad-band energy spectrum, X-ray spectral variability as a function of pulse phase (which are not predicted by the magnetar model), and X-ray bursts (which cannot be explained in terms of standard accretion models). We present the results obtained from an extensive multi-wavelength observational campaign carried out with the NTT and CFHT for the optical/IR bands, and XMM and Chandra (plus BeppoSAX archival data) in X-rays. Based on these results and those reported in the literature, the IR-to-X-ray emission of AXPs is compared.

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Induction of floquet topological phases in honeycomb nanoribbon irradiated by circularly polarized laser field

International Journal of Modern Physics B ◽

10.1142/s0217979221501800 ◽

2021 ◽

pp. 2150180

Author(s):

Chol Jun Kang ◽

Mun Gwon Jo

Keyword(s):

Energy Spectrum ◽

Laser Field ◽

Low Frequency ◽

Edge States ◽

Circularly Polarized ◽

Properties Of Materials ◽

The Stability ◽

External Time ◽

Time Periodic ◽

Topological Phase Transitions

The stability of the existence of the topological properties even in non-equilibrium condition such as irradiation of external time-periodic perturbation paves the way for designing and controlling the properties of materials. We study the change in the structure of the quasi-energy spectrum under the influence of the circularly polarized laser field with various intensities. The system is two-dimensional honeycomb nanoribbon of having zig-zag edges. Two cases where the onsite energies are present and absent are considered. We find that the topological phase transitions occur at some critical intensities of the laser field in both cases, which are recognized by the gap closing, the appearance of two crossing edge states, and sudden raise of the first Chern number from 0 to 1. The critical laser intensity is raised when either the frequency increases or the width of the ribbon decreases. Furthermore, band folding is observed in low-frequency domain in the quasi-energy spectrum and becomes more pronounced for the lower frequencies.

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Application of Wavelet Packet Energy Spectrum in Micro Motor Fault Diagnosis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.3159 ◽

2013 ◽

Vol 726-731 ◽

pp. 3159-3162

Author(s):

Sheng Yi Chen ◽

Gui Tang Wang ◽

Shou Lei Sun ◽

Qiang Zhou

Keyword(s):

Fault Diagnosis ◽

Energy Spectrum ◽

Frequency Band ◽

Wavelet Packet ◽

Reconstruction Algorithm ◽

Mechanical Equipment ◽

Vibration Signals ◽

Band Energy ◽

Status Information ◽

Frequency Band Energy

To diagnosis vibration signals of micro motor in several different fault types a method based on wavelet packet energy spectrum is presented, the energy on each Sub-frequency band, which are Calculated by Wavelet packet decomposition and reconstruction algorithm, are used to normalization process.Under both circumstances of normal working and unmoral working of mechanical equipment,there exist evident differences among the Sub-frequency band energy after the decomposition of wavelet packet, which energy contains a wealth of micro motor running status information and the eigenvectors is structured by the Sub-frequency band energy spectrum can establish energy and Fault mapping relationship.The preliminary experimental results show that it is effective to use the wavelet packet-energy spectrum in micro motor fault diagnosis .

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Valence band energy spectrum of HgTe quantum wells with an inverted band structure

Physical Review B ◽

10.1103/physrevb.96.035310 ◽

2017 ◽

Vol 96 (3) ◽

Cited By ~ 17

Author(s):

G. M. Minkov ◽

V. Ya. Aleshkin ◽

O. E. Rut ◽

A. A. Sherstobitov ◽

A. V. Germanenko ◽

...

Keyword(s):

Energy Spectrum ◽

Band Structure ◽

Quantum Wells ◽

Valence Band ◽

Band Energy ◽

Valence Band Energy

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Energy spectrum of edge states of a quantum dot in an external magnetic field

Physics Letters A ◽

10.1016/0375-9601(94)90765-x ◽

1994 ◽

Vol 190 (3-4) ◽

pp. 341-344 ◽

Cited By ~ 3

Author(s):

L.A. Falkovsky ◽

S. Klama

Keyword(s):

Magnetic Field ◽

Energy Spectrum ◽

External Magnetic Field ◽

Quantum Dot ◽

Edge States

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Влияние электрон-дырочной асимметрии на электронную структуру спиральных краевых состояний в квантовой яме HgTe/HgCdTe

Физика твердого тела ◽

10.21883/ftt.2020.03.49012.629 ◽

2020 ◽

Vol 62 (3) ◽

pp. 447

Author(s):

М.В. Дурнев

Keyword(s):

Electronic Structure ◽

Energy Spectrum ◽

Quantum Wells ◽

Wave Functions ◽

Optical Transitions ◽

Edge States ◽

Matrix Elements ◽

Electron Hole ◽

G Factor ◽

Analytical Expressions

We study the effects of electron-hole asymmetry on the electronic structure of helical edge states in HgTe/HgCdTe quantum wells. In the framework of the four-band kp-model, which takes into account the absence of a spacial inversion centre, we obtain analytical expressions for the energy spectrum and wave functions of edge states, as well as the effective g-factor tensor and matrix elements of electro-dipole optical transitions between the spin branches of the edge electrons. We show that when two conditions - electron-hole asymmetry and the absence of an inversion centre - are simultaneously satisfied, the spectrum of edge electrons deviates from the linear one, and we obtain the corresponding corrections.

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Is the edge states energy spectrum of a 2D topological insulator linear?

Физика и техника полупроводников ◽

10.21883/ftp.2018.04.45833.22 ◽

2018 ◽

Vol 52 (4) ◽

pp. 484

Author(s):

M.V. Entin ◽

M.M. Mahmoodian ◽

L.I. Magarill

Keyword(s):

Energy Spectrum ◽

Topological Insulator ◽

Transport Phenomena ◽

Edge State ◽

Edge States ◽

State Models

AbstractThe linearity of the edge states spectrum in a 2D topological insulator, important for various transport phenomena, is studied. Different edge state models are examined. It is found that, in some of them, the linearity is perfect, while, in others, the linearity is approximate.

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