scholarly journals Radiative corrections to the long-wavelength optical-mode spectrum of the electron-phonon model: Absence of mode-splitting effects and hardening of the mode

1997 ◽  
Vol 56 (21) ◽  
pp. 13731-13733 ◽  
Author(s):  
A. S. Alexandrov ◽  
J. R. Schrieffer
Keyword(s):  
Radiative Corrections ◽  
Optical Mode ◽  
Long Wavelength ◽  
Mode Spectrum ◽  
Mode Splitting ◽  
Phonon Model

scholarly journals Theoretical study of negative optical mode splitting inLaAlO3

2016 ◽  
Vol 93 (13) ◽  
Author(s):  
Kurt D. Fredrickson ◽  
Chungwei Lin ◽  
Stefan Zollner ◽  
Alexander A. Demkov
Keyword(s):  
Theoretical Study ◽  
Optical Mode ◽  
Mode Splitting

scholarly journals Polynomials for crystal frameworks and the rigid unit mode spectrum

2014 ◽  
Vol 372 (2008) ◽  
pp. 20120030 ◽  
Author(s):  
S. C. Power
Keyword(s):  
Explicit Formula ◽  
Algebraic Variety ◽  
Matrix Function ◽  
Singular Points ◽  
Cubic Symmetry ◽  
Long Wavelength ◽  
Wavelength Limit ◽  
Mode Spectrum ◽  
Harmonic Excitations ◽  
The Matrix

To each discrete translationally periodic bar-joint framework in , we associate a matrix-valued function defined on the d -torus. The rigid unit mode (RUM) spectrum of is defined in terms of the multi-phases of phase-periodic infinitesimal flexes and is shown to correspond to the singular points of the function and also to the set of wavevectors of harmonic excitations which have vanishing energy in the long wavelength limit. To a crystal framework in Maxwell counting equilibrium, which corresponds to being square, the determinant of gives rise to a unique multi-variable polynomial . For ideal zeolites, the algebraic variety of zeros of on the d -torus coincides with the RUM spectrum. The matrix function is related to other aspects of idealized framework rigidity and flexibility, and in particular leads to an explicit formula for the number of supercell-periodic floppy modes. In the case of certain zeolite frameworks in dimensions two and three, direct proofs are given to show the maximal floppy mode property (order N ). In particular, this is the case for the cubic symmetry sodalite framework and some other idealized zeolites.

scholarly journals Anti-$\mathcal{PT}$-symmetric Kerr gyroscope

2021 ◽  
Author(s):  
Huilai Zhang ◽  
Meiyu Peng ◽  
Xun-Wei Xu ◽  
Hui Jing
Keyword(s):  
Detection Threshold ◽  
Kerr Nonlinearity ◽  
Optical Mode ◽  
Spectral Singularities ◽  
Exceptional Points ◽  
Rotation Measurement ◽  
Mode Splitting ◽  
External Signals ◽  
Spectral Responses ◽  
Conventional Device

Abstract Non-Hermitian systems can exhibit unconventional spectral singularities called exceptional points (EPs). Various EP sensors have been fabricated in recent years, showing strong spectral responses to external signals. Here we propose how to achieve a nonlinear anti-parity-time ($\mathcal{APT}$) gyroscope by spinning an optical resonator. We show that, in the absence of any nonlinearity, the sensitivity or optical mode splitting of the linear device can be magnified up to 3 orders than that of the conventional device without EPs. Remarkably, the $\mathcal{APT}$ symmetry can be broken when including the Kerr nonlinearity of the materials and, as the result, the detection threshold can be significantly lowered, i.e., much weaker rotations which are well beyond the ability of a linear gyroscope can now be detected with the nonlinear device. Our work shows the powerful ability of $\mathcal{APT}$ gyroscopes in practice to achieve ultrasensitive rotation measurement.

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