Parametric instabilities induced by the coupling excitation between the high frequency quantum Langmuir waves and the low frequency quantum ion-acoustic waves in single-walled carbon nanotubes are studied with a quant...Parametric instabilities induced by the coupling excitation between the high frequency quantum Langmuir waves and the low frequency quantum ion-acoustic waves in single-walled carbon nanotubes are studied with a quantum Zakharov model. By linearizing the quantum hydrodynamic equations, we get the dispersion relations for the high frequency quantum Langmuir wave and the low frequency quantum ion-acoustic wave. Using two-time scale method, we obtain the quantum Zaharov model in the cylindrical coordinates. Decay instability and four-wave instability are discussed in detail. It is shown that the carbon nanotube＇s radius, the equilibrium discrete azimuthal quantum number, the perturbed discrete azimuthal quantum number, and the quantum parameter all play a crucial role in the instabilities.展开更多
We present an analytical study on the dynamics of dark solitons in superfluid Fermi gases.By using the modified lens-type transformation,the dynamical equation of superfluid Fermi gases is reduced to a modified one-di...We present an analytical study on the dynamics of dark solitons in superfluid Fermi gases.By using the modified lens-type transformation,the dynamical equation of superfluid Fermi gases is reduced to a modified one-dimensional nonlinear Shor?dinger equation(NLSE).Once again,by using the reductive perturbation method,the NLSE is reduced to a standard Korteweg-de Vries equation which may be useful for understanding the dynamics of dark solitons in superfluid Fermi gases.The existence of dark soliton solutions in the Fermi gases is provided.In particular,we show that,by manipulating and controlling the scattering length between Fermi atomics of different components and the external potential,the soliton's parameters(amplitude and width)can be changed in a controllable way.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11274255 and 10975114)the Natural Science Foundation of Gansu Province of China (Grant No.2011GS04358)the Creation of Science and Technology of Northwest Normal University of China (Grant No.NWNU-KJCXGC-03-48)
文摘Parametric instabilities induced by the coupling excitation between the high frequency quantum Langmuir waves and the low frequency quantum ion-acoustic waves in single-walled carbon nanotubes are studied with a quantum Zakharov model. By linearizing the quantum hydrodynamic equations, we get the dispersion relations for the high frequency quantum Langmuir wave and the low frequency quantum ion-acoustic wave. Using two-time scale method, we obtain the quantum Zaharov model in the cylindrical coordinates. Decay instability and four-wave instability are discussed in detail. It is shown that the carbon nanotube＇s radius, the equilibrium discrete azimuthal quantum number, the perturbed discrete azimuthal quantum number, and the quantum parameter all play a crucial role in the instabilities.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274255 and 11305132the Natural Science Foundation of Gansu Province under Grant No 2011GS04358Creation of Science and Technology of Northwest Normal University under Grant Nos NWNU-KJCXGC-03-48 and NWNU-LKQN-12-12.
文摘We present an analytical study on the dynamics of dark solitons in superfluid Fermi gases.By using the modified lens-type transformation,the dynamical equation of superfluid Fermi gases is reduced to a modified one-dimensional nonlinear Shor?dinger equation(NLSE).Once again,by using the reductive perturbation method,the NLSE is reduced to a standard Korteweg-de Vries equation which may be useful for understanding the dynamics of dark solitons in superfluid Fermi gases.The existence of dark soliton solutions in the Fermi gases is provided.In particular,we show that,by manipulating and controlling the scattering length between Fermi atomics of different components and the external potential,the soliton's parameters(amplitude and width)can be changed in a controllable way.
