scholarly journals Phonon-number-resolving detection of multiple local phonon modes in trapped ions

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Ryutaro Ohira ◽  
Takashi Mukaiyama ◽  
Kenji Toyoda
Keyword(s):  
Trapped Ions ◽  
Phonon Modes ◽  
Phonon Number

MULTI-COMPONENT SQUEEZED COHERENT STATE FOR N TRAPPED IONS IN ANY POSITION OF A STANDING WAVE

2005 ◽  
Vol 19 (15) ◽  
pp. 729-735
Author(s):  
FANG-FANG LUO ◽  
WEN-XING YANG ◽  
JIAO-MEI LI ◽  
HUA-LING SHU ◽  
HUA GUAN ◽  
...  
Keyword(s):  
Phase Space ◽  
Coherent State ◽  
Standing Wave ◽  
Carrier Frequency ◽  
Coherent States ◽  
Laser Intensity ◽  
Trapped Ions ◽  
Squeezed Coherent State ◽  
Phonon Number ◽  
Wave Laser

We proposed a scheme to generate a multi-component squeezed coherent states with arbitrary coefficients on a line in phase space for multiple trapped ions radiated by a single standing-wave laser whose carrier frequency is tuned to the ions transition. In the scheme each ion does not need to be exactly positioned at the node of the standing wave. Furthermore, our scheme may allow the generation of a multi-component squeezed coherent states with large mean phonon number in a fast way by choosing a suitable laser intensity, which is important in view of de-coherence processes.

scholarly journals Phonons in Short-Period GaN/AlN Superlattices: Group-Theoretical Analysis, Ab initio Calculations, and Raman Spectra

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 286
Author(s):  
Valery Davydov ◽  
Evgenii Roginskii ◽  
Yuri Kitaev ◽  
Alexander Smirnov ◽  
Ilya Eliseyev ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Raman Spectra ◽  
Density Functional ◽  
Structural Characteristics ◽  
Vibrational Modes ◽  
Phonon Modes ◽  
Short Period ◽  
Group Theoretical Analysis

We report the results of experimental and theoretical studies of phonon modes in GaN/AlN superlattices (SLs) with a period of several atomic layers, grown by submonolayer digital plasma-assisted molecular-beam epitaxy, which have a great potential for use in quantum and stress engineering. Using detailed group-theoretical analysis, the genesis of the SL vibrational modes from the modes of bulk AlN and GaN crystals is established. Ab initio calculations in the framework of the density functional theory, aimed at studying the phonon states, are performed for SLs with both equal and unequal layer thicknesses. The frequencies of the vibrational modes are calculated, and atomic displacement patterns are obtained. Raman spectra are calculated and compared with the experimental ones. The results of the ab initio calculations are in good agreement with the experimental Raman spectra and the results of the group-theoretical analysis. As a result of comprehensive studies, the correlations between the parameters of acoustic and optical phonons and the structure of SLs are obtained. This opens up new possibilities for the analysis of the structural characteristics of short-period GaN/AlN SLs using Raman spectroscopy. The results obtained can be used to optimize the growth technologies aimed to form structurally perfect short-period GaN/AlN SLs.

scholarly journals Blockade of phonon hopping in trapped ions in the presence of multiple local phonons

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Ryutaro Ohira ◽  
Shota Kume ◽  
Kyoichi Takayama ◽  
Silpa Muralidharan ◽  
Hiroki Takahashi ◽  
...  
Keyword(s):  
Trapped Ions

Axial guided wave characteristics in functionally graded one-dimensional hexagonal piezoelectric quasi-crystal cylinders

2021 ◽  
pp. 108128652110134
Author(s):  
B. Zhang ◽  
X.H. Wang ◽  
L. Elmaimouni ◽  
J.G. Yu ◽  
X.M. Zhang
Keyword(s):  
Coupling Effect ◽  
Energy Conversion Efficiency ◽  
Guided Wave ◽  
Functionally Graded ◽  
Phonon Modes ◽  
One Dimensional ◽  
Longitudinal Modes ◽  
Wave Characteristics ◽  
Piezoelectric Effects ◽  
Hollow Cylinders

In one-dimensional hexagonal piezoelectric quasi-crystals, there exist the phonon–phason, electro–phonon, and electro–phason couplings. Therefore, the phonon–phason coupling and piezoelectric effects on axial guided wave characteristics in one-dimensional hexagonal functionally graded piezoelectric quasi-crystal (FGPQC) cylinders are investigated by utilizing the Legendre polynomial series method. The dispersion curves and cut-off frequencies are illustrated. Wave characteristics in three hollow cylinders with different quasi-periodic directions are comparatively studied. Some new wave phenomena are revealed: the phonon–phason coupling and piezoelectric effects on the longitudinal and torsional phonon modes ( N = 0) vary as the quasi-periodic direction changes; the phonon–phason coupling effect on flexural–torsional modes in the r-, z-FGPQC hollow cylinders, and on flexural–longitudinal modes in ϑ-FGPQC hollow cylinders increases as N increases. The corresponding results obtained in this work lay the theoretical foundation for the design and manufacture of piezoelectric transducers with high resolution and energy-conversion efficiency.

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