The quantum fluctuations of the charge and current in a non-dissipative mesoscopic circuit with coupled inductors and capacitors are studied for the squeezed vacuum state.The influence of the phase angle upon the quan...The quantum fluctuations of the charge and current in a non-dissipative mesoscopic circuit with coupled inductors and capacitors are studied for the squeezed vacuum state.The influence of the phase angle upon the quantum fluctuations is discussed in particular.Our results indicate that when the circuit parameters remain constant and the phasesθof the two circuits are equal,the squeezing of the charge or its conjugate variable increases.When the difference of the two phases equalsπ,the squeezing will deteriorate.Therefore,if we want to decrease the quantum noise,we should not only control the amplitude r,but also control the phaseθcarefully.展开更多
The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functio...The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functional theory,the vacancy formation energy and vacancy(Vac)−H interaction energies are calculated.The results show that vacancies have a strong trapping effect on H atoms,which lowers the formation energy of Vac-nH clusters substantially.The concentration of Vac−nH clusters is evaluated using a statistical model and the dependence of the concentration on the H−to-M ratio is obtained.It is shown that the concentration of the Vac-nH clusters can be as high as 10−3 at 573 K,i.e.one Vac-nH cluster per 1000 atoms,in good agreement with the experimental observations.展开更多
文摘The quantum fluctuations of the charge and current in a non-dissipative mesoscopic circuit with coupled inductors and capacitors are studied for the squeezed vacuum state.The influence of the phase angle upon the quantum fluctuations is discussed in particular.Our results indicate that when the circuit parameters remain constant and the phasesθof the two circuits are equal,the squeezing of the charge or its conjugate variable increases.When the difference of the two phases equalsπ,the squeezing will deteriorate.Therefore,if we want to decrease the quantum noise,we should not only control the amplitude r,but also control the phaseθcarefully.
基金Supported by the National Natural Science Foundation of China under Grant No 11064004the Natural Science Foundation of Jiangxi Province under Grant No 2010GZW0028.
文摘The vacancy and H interactions in bcc Nb are important due to their implication in understanding of the H induced damage of Nb metallic membrane used in H2 separation and purification application.Using density functional theory,the vacancy formation energy and vacancy(Vac)−H interaction energies are calculated.The results show that vacancies have a strong trapping effect on H atoms,which lowers the formation energy of Vac-nH clusters substantially.The concentration of Vac−nH clusters is evaluated using a statistical model and the dependence of the concentration on the H−to-M ratio is obtained.It is shown that the concentration of the Vac-nH clusters can be as high as 10−3 at 573 K,i.e.one Vac-nH cluster per 1000 atoms,in good agreement with the experimental observations.
