By using the closed orbit theory, the photodetachment cross section of H- in a static electric field between two parallel elastic interfaces is derived and calculated. It is found that the photodetachment cross sectio...By using the closed orbit theory, the photodetachment cross section of H- in a static electric field between two parallel elastic interfaces is derived and calculated. It is found that the photodetachment cross section depends on the electric field and the distance between the ion and the elastic interface. The oscillation of the cross section becomes more complicated than in the case of H- near one elastic interface. The results show that near the detachment threshold, the influence of the additional interface can be neglected. But with the increase of the energy, its influence becomes great. At some energies, the cross sections display sharp peaks, contrasting with the staircase structure when only one interface exists. This study provides a new understanding of the photodetachment process of H- in the presence of external field and interfaces.展开更多
Based on closed-orbit theory, the influence of an interface modifier on the photodetachment of H^- in an electric field near a metal surface is studied. It is demonstrated that the interface strengthens the oscillatio...Based on closed-orbit theory, the influence of an interface modifier on the photodetachment of H^- in an electric field near a metal surface is studied. It is demonstrated that the interface strengthens the oscillations in the photodetachment cross section. However, when the electric field environments are different, the strengthening oscillations are caused by different sources. When the electric field direction is upward, the interface enhances the oscillations by shortening the period and the action of the closed orbit. When the electric field direction is downward, the interface strengthens the oscillations either by extending the coherent energy range or by increasing the total number of the closed orbits. We hope that our results will be conducive to the understanding of the photodetachment process of negative ions near interfaces, cavities and ion traps.展开更多
According to the closed-orbit theory, we study the influence of elastic interface on the photodetachment of H- near a metallic sphere surface. First, we give a clear physical description of the detached electron movem...According to the closed-orbit theory, we study the influence of elastic interface on the photodetachment of H- near a metallic sphere surface. First, we give a clear physical description of the detached electron movement between the elastic interface and the metallic sphere surface. Then we put forward an analytical formula for calculating the photodetachment cross section of this system. Our study suggests that the photodetachment cross section of H is changed with the distance between the elastic interface and H^-. Compared with the photodetachment cross section of H^- near a metallic sphere surface without the elastic interface, the cross section of our system oscillates and its oscillation is strengthened with the decrease of the distance from the elastic interface to H^-. In additon, our calcuation results suggest that the influence of the elastic interface becomes much more significant when it is located in the lower half space rather than in the upper half space. Therefore, we can control the photodetachment of H^- near a metallic sphere surface by changing the position of the elastic interface. We hope that our work is conducive to the understanding of the photodetachment process of negative ions near interfaces, cavities and ion traps.展开更多
We derive a formula for double-pulse spectra from closed-orbit theory. We then calculate the double-pulsephotodetachment spectra of H- in the presence of parallel electric and magnetic fields. We analyze the spectra i...We derive a formula for double-pulse spectra from closed-orbit theory. We then calculate the double-pulsephotodetachment spectra of H- in the presence of parallel electric and magnetic fields. We analyze the spectra in termsof closed-orbits of the system. We suggest a method for the measurement of a phase associated with each closed-orbit.展开更多
The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cro...The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cross section of this system is put forward. It is found that the photodetachment cross section of this system is nearly unaffected for the weak oscillating electric field strength, but oscillates complicatedly when the oscillating electric field strength turns strong. In addition, the frequency of the harmonic potential and the oscillating electric field (the frequency of the harmonic potential and the frequency of the oscillating electric field are the same in the paper, unless otherwise stated.) can also affect the photodetachment dynamics of this system. With the increase of the frequency in the harmonic potential and the oscillating electric field, the number of the closed orbits for the detached electrons increased, which makes the oscillatory structure in the photodetachment cross section much more complex. Our study presents an intuitive understanding of the photodetachment dynamics driven by a harmonic potential plus an oscillating electric field from a space and time dependent viewpoint. This study is very useful in guiding the future experimental research for the photodetachment dynamics in the electric field both changing with space and time.展开更多
The influence of electric field on the photodetachment of H- near a metal surface is investigated based on the closed-orbit theory. It is found that the photodetachment of H- near a metal surface is not only related t...The influence of electric field on the photodetachment of H- near a metal surface is investigated based on the closed-orbit theory. It is found that the photodetachment of H- near a metal surface is not only related to the electric field strength but also to the electric field direction. If the electric field is along the +z axis, it can strengthen the oscillation in the photodetachment cross section. However, if the electric field is along the -z axis, since the direction of electric field force is opposite to that of static-image force caused by the metal surface, the situation becomes much more complicated. When the electric field is very weak, its influence can be neglected. The photodetachment cross section is nearly the same as that when a single metal surface exists. When the electric field strength is strong enough, the electric field force is able to counteract the metallic attraction, therefore no closed orbit is formed. If the electric field continues to increase until its influence becomes dominant, the photodetachment cross section approaches the case of the photodetachment of H^- in an electric field. Our results may be useful for guiding future experimental studies on the photodetachment of negative ions near surfaces.展开更多
Based on the closed-orbit theory, the magnetic field effect in the photodetachment of negative ion in the electric field near a metal surface is studied for the first time. The results show that the magnetic field can...Based on the closed-orbit theory, the magnetic field effect in the photodetachment of negative ion in the electric field near a metal surface is studied for the first time. The results show that the magnetic field can produce a significant effect on the photodetachment of negative ion near a metal surface. Besides the closed orbits previously found by Duet al. for the H in the electric field near a metal surface (J. Phys. B 43 035002 (2010)), some additional closed orbits are produced due to the effect of magnetic field. For a given ion surface distance and an electric field strength, the cross section depends sensitively on the magnetic field strength. As the magnetic field strength is very small, its influence can be neglected. With the increase of the magnetic field strength, the number of the closed orbits increases greatly and the oscillation in the cross section becomes much more complex. Therefore we can control the photodetachment cross section of the negative ion by changing the magnetic field strength. We hope that our results may guide future experimental studies for the photodetachment process of negative ion in the presence of external fields and surfaces.展开更多
Based on closed-orbit theory, the photodetachment of H- in a gradient electric field near a metal surface is studied. It is demonstrated that the gradient electric field has a significant influence on the photodetachm...Based on closed-orbit theory, the photodetachment of H- in a gradient electric field near a metal surface is studied. It is demonstrated that the gradient electric field has a significant influence on the photodetachment of negative ions near a metal surface. With the increase of the gradient of the electric field, the oscillation in the photodetachment cross section becomes strengthened. Besides, in contrast to the photodetachment of H- near a metal surface in a uniform electric field, the oscillating amplitude and the oscillating region in the cross section of a gradient electric field also become enlarged. Therefore, we can use the gradient electric field to control the photodetachment of negative ions near a metal surface. We hope that our results will be useful for understanding the photodetachment of negative ions in the vicinity of surfaces, cavities, and ion traps.展开更多
The photodetachment of a hydrogen negative ion inside a circular microcavity is studied based on the semiclassical closed orbit theory. The closed orbit of the photo-detached electron in a circular microcavity is inve...The photodetachment of a hydrogen negative ion inside a circular microcavity is studied based on the semiclassical closed orbit theory. The closed orbit of the photo-detached electron in a circular microcavity is investigated and the photodetachment cross section of this system is calculated. The calculation result suggests that oscillating structure appears in the photodetachment cross section, which is caused by the interference effects of the returning electron waves with the outgoing waves traveling along the closed orbits. Besides, our study suggests that the photodetachment cross section of the negative ions depends on the laser polarization sensitively. In order to show the correspondence between the cross section and the closed orbits of the detached electron clearly, we calculate the Fourier transformation of the cross section and find that each peak corresponds to the length of one closed orbit. We hope that our results will be useful for understanding the photodetachment process of negative ions or the electron transport in a microcavity.展开更多
We calculate the photodetachment cross sections of H- in a gradient electric field based on traditional quantum approach. The system provides a rare example that the formulas for the cross sections can be explicitly d...We calculate the photodetachment cross sections of H- in a gradient electric field based on traditional quantum approach. The system provides a rare example that the formulas for the cross sections can be explicitly derived by both the quantum approach and closed-orbit theory. The quantum results are compared with those of the closed-orbit theory. The correct phase values in the closed-orbit theory are essential and necessary to produce accurate cross sections. Our quantum results remove some previous ambiguities in assigning the phase values in the closed-orbit theory (G. C. Yang and M. L. Du 2007 Phys. Rev. A 75 029904E).展开更多
The photodetachment of H-near a hard wall is investigated with linear polarized laser light travelling in arbitrary direction θL with respect to the z axis. An analytical formula for the total cross section is derive...The photodetachment of H-near a hard wall is investigated with linear polarized laser light travelling in arbitrary direction θL with respect to the z axis. An analytical formula for the total cross section is derived using semi-classical closed orbit theory, which consists of two terms, i.e., the smooth background term and the oscillatory term with an extra factor 2(θL). This factor controls oscillations in the total photodetachment cross section. The amplitude of oscillation is maximum at θL = 0 when the laser polarization direction is perpendicular to the wall and it approaches zero at θL = π /2when the laser polarization direction is parallel to the wall. It is also observed that the total cross section depends on the source–wall distance and it reduces to a free space case when the wall is at infinite distance from the source.展开更多
The photodetachment cross section of H- in a linear harmonic oscillator potential is investigated. This system pro- vides a rare example that can be studied analytically by both quantum and semiclassical methods with ...The photodetachment cross section of H- in a linear harmonic oscillator potential is investigated. This system pro- vides a rare example that can be studied analytically by both quantum and semiclassical methods with some approxi- mations. The formulas of the cross section for different laser polarization directions are explicitly derived by both the traditional quantum approach and closed-orbit theory. In the traditional quantum approach, we calculate the cross sections in coordinate representation and momentum representation, and get the same formulas. We compare the quantum formulas with closed-orbit theory formulas, and find that when the detachment electron energy is larger than hco, where co is the frequency of the oscillator potential, the quantum results are shown to be in good agreement with the semiclassical results.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10604045)
文摘By using the closed orbit theory, the photodetachment cross section of H- in a static electric field between two parallel elastic interfaces is derived and calculated. It is found that the photodetachment cross section depends on the electric field and the distance between the ion and the elastic interface. The oscillation of the cross section becomes more complicated than in the case of H- near one elastic interface. The results show that near the detachment threshold, the influence of the additional interface can be neglected. But with the increase of the energy, its influence becomes great. At some energies, the cross sections display sharp peaks, contrasting with the staircase structure when only one interface exists. This study provides a new understanding of the photodetachment process of H- in the presence of external field and interfaces.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11074104 and 10604045)the University Science & Technology Planning Program of Shandong Province of China (Grant No.J09LA02)the Discipline Construction Fund of Ludong University of China
文摘Based on closed-orbit theory, the influence of an interface modifier on the photodetachment of H^- in an electric field near a metal surface is studied. It is demonstrated that the interface strengthens the oscillations in the photodetachment cross section. However, when the electric field environments are different, the strengthening oscillations are caused by different sources. When the electric field direction is upward, the interface enhances the oscillations by shortening the period and the action of the closed orbit. When the electric field direction is downward, the interface strengthens the oscillations either by extending the coherent energy range or by increasing the total number of the closed orbits. We hope that our results will be conducive to the understanding of the photodetachment process of negative ions near interfaces, cavities and ion traps.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11074104 and 11374133)the Shandong Provincial Higher Educational Science and Technology Program,China (Grant No.J13LJ04)
文摘According to the closed-orbit theory, we study the influence of elastic interface on the photodetachment of H- near a metallic sphere surface. First, we give a clear physical description of the detached electron movement between the elastic interface and the metallic sphere surface. Then we put forward an analytical formula for calculating the photodetachment cross section of this system. Our study suggests that the photodetachment cross section of H is changed with the distance between the elastic interface and H^-. Compared with the photodetachment cross section of H^- near a metallic sphere surface without the elastic interface, the cross section of our system oscillates and its oscillation is strengthened with the decrease of the distance from the elastic interface to H^-. In additon, our calcuation results suggest that the influence of the elastic interface becomes much more significant when it is located in the lower half space rather than in the upper half space. Therefore, we can control the photodetachment of H^- near a metallic sphere surface by changing the position of the elastic interface. We hope that our work is conducive to the understanding of the photodetachment process of negative ions near interfaces, cavities and ion traps.
文摘We derive a formula for double-pulse spectra from closed-orbit theory. We then calculate the double-pulsephotodetachment spectra of H- in the presence of parallel electric and magnetic fields. We analyze the spectra in termsof closed-orbits of the system. We suggest a method for the measurement of a phase associated with each closed-orbit.
基金supported by the National Natural Science Foundation of China(Grant No.11374133)the Taishan Scholars Project of Shandong Province,China(Grant No.ts2015110055)
文摘The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cross section of this system is put forward. It is found that the photodetachment cross section of this system is nearly unaffected for the weak oscillating electric field strength, but oscillates complicatedly when the oscillating electric field strength turns strong. In addition, the frequency of the harmonic potential and the oscillating electric field (the frequency of the harmonic potential and the frequency of the oscillating electric field are the same in the paper, unless otherwise stated.) can also affect the photodetachment dynamics of this system. With the increase of the frequency in the harmonic potential and the oscillating electric field, the number of the closed orbits for the detached electrons increased, which makes the oscillatory structure in the photodetachment cross section much more complex. Our study presents an intuitive understanding of the photodetachment dynamics driven by a harmonic potential plus an oscillating electric field from a space and time dependent viewpoint. This study is very useful in guiding the future experimental research for the photodetachment dynamics in the electric field both changing with space and time.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10604045)the University Science & Technology Planning Program of Shandong Province (Grant No. J09LA02)the Discipline Construction Fund of Ludong University
文摘The influence of electric field on the photodetachment of H- near a metal surface is investigated based on the closed-orbit theory. It is found that the photodetachment of H- near a metal surface is not only related to the electric field strength but also to the electric field direction. If the electric field is along the +z axis, it can strengthen the oscillation in the photodetachment cross section. However, if the electric field is along the -z axis, since the direction of electric field force is opposite to that of static-image force caused by the metal surface, the situation becomes much more complicated. When the electric field is very weak, its influence can be neglected. The photodetachment cross section is nearly the same as that when a single metal surface exists. When the electric field strength is strong enough, the electric field force is able to counteract the metallic attraction, therefore no closed orbit is formed. If the electric field continues to increase until its influence becomes dominant, the photodetachment cross section approaches the case of the photodetachment of H^- in an electric field. Our results may be useful for guiding future experimental studies on the photodetachment of negative ions near surfaces.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11074104 and 10604045)the University Science and Technology Planning Program of Shandong Province of China (Grant No. J09LA02)
文摘Based on the closed-orbit theory, the magnetic field effect in the photodetachment of negative ion in the electric field near a metal surface is studied for the first time. The results show that the magnetic field can produce a significant effect on the photodetachment of negative ion near a metal surface. Besides the closed orbits previously found by Duet al. for the H in the electric field near a metal surface (J. Phys. B 43 035002 (2010)), some additional closed orbits are produced due to the effect of magnetic field. For a given ion surface distance and an electric field strength, the cross section depends sensitively on the magnetic field strength. As the magnetic field strength is very small, its influence can be neglected. With the increase of the magnetic field strength, the number of the closed orbits increases greatly and the oscillation in the cross section becomes much more complex. Therefore we can control the photodetachment cross section of the negative ion by changing the magnetic field strength. We hope that our results may guide future experimental studies for the photodetachment process of negative ion in the presence of external fields and surfaces.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11074104 and 10604045)the Higher Education Science and Technology Program of Shandong Province, China (Grant No. J09LA02)the University Student's Science and Technology Innovation Fund of Ludong University, China (Grant No. 10g003)
文摘Based on closed-orbit theory, the photodetachment of H- in a gradient electric field near a metal surface is studied. It is demonstrated that the gradient electric field has a significant influence on the photodetachment of negative ions near a metal surface. With the increase of the gradient of the electric field, the oscillation in the photodetachment cross section becomes strengthened. Besides, in contrast to the photodetachment of H- near a metal surface in a uniform electric field, the oscillating amplitude and the oscillating region in the cross section of a gradient electric field also become enlarged. Therefore, we can use the gradient electric field to control the photodetachment of negative ions near a metal surface. We hope that our results will be useful for understanding the photodetachment of negative ions in the vicinity of surfaces, cavities, and ion traps.
基金the National Natural Science Foundation of China(Grant No.11074104)the Higher Educational Science and Technology Program of Shandong Province,China(Grant No.J13LJ04)the University Student's Science&Technology Innovation Fund of Ludong University,China(Grant No.12z004)
文摘The photodetachment of a hydrogen negative ion inside a circular microcavity is studied based on the semiclassical closed orbit theory. The closed orbit of the photo-detached electron in a circular microcavity is investigated and the photodetachment cross section of this system is calculated. The calculation result suggests that oscillating structure appears in the photodetachment cross section, which is caused by the interference effects of the returning electron waves with the outgoing waves traveling along the closed orbits. Besides, our study suggests that the photodetachment cross section of the negative ions depends on the laser polarization sensitively. In order to show the correspondence between the cross section and the closed orbits of the detached electron clearly, we calculate the Fourier transformation of the cross section and find that each peak corresponds to the length of one closed orbit. We hope that our results will be useful for understanding the photodetachment process of negative ions or the electron transport in a microcavity.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10804066 and 11074260)the Natural Science Foundation of Shanxi Province of China (Grant No. 2009011004)
文摘We calculate the photodetachment cross sections of H- in a gradient electric field based on traditional quantum approach. The system provides a rare example that the formulas for the cross sections can be explicitly derived by both the quantum approach and closed-orbit theory. The quantum results are compared with those of the closed-orbit theory. The correct phase values in the closed-orbit theory are essential and necessary to produce accurate cross sections. Our quantum results remove some previous ambiguities in assigning the phase values in the closed-orbit theory (G. C. Yang and M. L. Du 2007 Phys. Rev. A 75 029904E).
基金financial support of the Higher Education Commission of Pakistan for this work under Startup Research Grant Project (No. IPFP/HRD/HEC/2014/1641)
文摘The photodetachment of H-near a hard wall is investigated with linear polarized laser light travelling in arbitrary direction θL with respect to the z axis. An analytical formula for the total cross section is derived using semi-classical closed orbit theory, which consists of two terms, i.e., the smooth background term and the oscillatory term with an extra factor 2(θL). This factor controls oscillations in the total photodetachment cross section. The amplitude of oscillation is maximum at θL = 0 when the laser polarization direction is perpendicular to the wall and it approaches zero at θL = π /2when the laser polarization direction is parallel to the wall. It is also observed that the total cross section depends on the source–wall distance and it reduces to a free space case when the wall is at infinite distance from the source.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11421063 and 11474079)the Natural Science Foundation of Shanxi Province,China(Grant No.2009011004)the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi Province,China
文摘The photodetachment cross section of H- in a linear harmonic oscillator potential is investigated. This system pro- vides a rare example that can be studied analytically by both quantum and semiclassical methods with some approxi- mations. The formulas of the cross section for different laser polarization directions are explicitly derived by both the traditional quantum approach and closed-orbit theory. In the traditional quantum approach, we calculate the cross sections in coordinate representation and momentum representation, and get the same formulas. We compare the quantum formulas with closed-orbit theory formulas, and find that when the detachment electron energy is larger than hco, where co is the frequency of the oscillator potential, the quantum results are shown to be in good agreement with the semiclassical results.
基金Supported by National Natural Science Foundation of China under Grant No. 10604045the University Science & Technology Planning Program of Shandong Province under Grant No. J09LA02+1 种基金the Education Department Foundation of Shandong Province under Grant No. J08LI03 the Discipline Construction Fund of Ludong University
文摘用关上的轨道理论, H 的 photodetachment 十字节?近,绝缘的表面被导出并且计算。结果证明绝缘的表面在电离阀值附近在否定离子的 photodetachment 过程上有大影响。在电离阀值上面, photodetachment 十字节开始震荡。随精力的增加,震荡的振幅减少,震荡的频率增加。在 H 的 photodetachment 十字节的摆动?面对绝缘的表面比 H 的 photodetachment 更大或小吗?没有表面。因为光子精力比批评价值 Epc 大,摆动的结构消失了并且 H 的 photodetachment 的盒子的生气的节途径吗?在任何外部地外面。为一个给定的分开电子的精力, photodetachment 十字节变得随离子表面距离的增加减少了。而且,绝缘的常数在 H 的 photodetachment 上有大影响 ? 。随绝缘的常数的增加,在生气的节的摆动变得增加。作为到无穷的绝缘的经常的增加,生气的节与 H 的 photodetachment 一样吗?接近金属表面。这研究在 H 的 photodetachment 过程上提供新理解吗?面对电介质出现。
基金The Natural Science Foundation for Youths of Shandong Province of China(No.ZR2014AQ022)the Project of Shandong Province Higher Education Science and Technology Program of China(No.J16LJ51)