We study the ultraslow optical solitons in a resonant three-level atomic system via electromagnetically induced transparency under a density-matrix （DM） approach. The results of linear and nonlinear optical properti...We study the ultraslow optical solitons in a resonant three-level atomic system via electromagnetically induced transparency under a density-matrix （DM） approach. The results of linear and nonlinear optical properties are compared with those obtained by using an amplitude variable （AV） approach. It is found that the results for both approaches are the same in the linear regime if the corresponding relations between the population-coherence decay rates in the DM approach and the energy-level decay rates in the AV approach are appropriately imposed. However, in the nonlinear regime there is a small difference for the self-phase modulation coefficient of the nonlinear SchrSdinger equation that governs the time evolution of probe pulse envelope. All analytical predicts are checked by numerical simulations.展开更多
This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields. This study shows that, by choosing app...This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields. This study shows that, by choosing appropriate physical parameters, self-modulation can precisely balance group velocity dispersion in the investigated system, leading to the formation of ultraslow optical solitons of the probe field. The proposed scheme may lead to the development of the controlled technique of optical buffers and optical delay lines.展开更多
Motile plant tissues can control their configurations and regulate their motion speed according to their specific requirements,which offer various protypes for biomimetic actuators with controlled motion speed.In this...Motile plant tissues can control their configurations and regulate their motion speed according to their specific requirements,which offer various protypes for biomimetic actuators with controlled motion speed.In this perspective,we focus on the speed control of plant tissues and the bioinspired strategies for speed regulation of artificial actuators.We begin with a summary to the strategies and mechanisms of motile plant tissues for controlling motion speed,ranging from ultrafast to ultraslow.We then exemplify the models for fabricating bioinspired artificial actuators and briefly discuss current application scenarios of actuators with varying speeds from ultrafast to ultraslow.Finally,we propose potential strategies for the speed regulation of actuators.展开更多
As relics of ancient ocean lithosphere,ophiolites are the most important petrological evidence for marking the sutures and also play a key role in reconstructing plate configuration.They also provide valuable windows ...As relics of ancient ocean lithosphere,ophiolites are the most important petrological evidence for marking the sutures and also play a key role in reconstructing plate configuration.They also provide valuable windows for studying crustal accretion and mantle processes occurring at modem ocean ridges.Abundant ophiolites are distributed along the Yarlung-Tsangpo suture and represent the relics of ocean lithosphere of the Neo-Tethys.They are characterized by an incomplete litho-stratigraphy,of which the mantle section is much thicker than the crustal section.Ocean crustal rocks outcropped in the Yarlung-Tsangpo ophiolites are much thinner than normal ocean crusts(~7 km)or even absent.Tectonic settings from which the Yarlung-Tsangpo ophiolites originated remain highly controversial,although an origin of the supra-subduction zone is prevailing.Moreover,their incomplete litho-stratigraphy has been commonly attributed to tectonic dismemberment during the late-stage emplacement after their formation.Nevertheless,such an incompleteness resembles the ocean lithosphere generated at modem ultraslow spreading ridges,such as the Southwest Indian Ridge(SWIR).In this paper,we present several lines of evidence that support the formation of the Yarlung-Tsangpo ophiolites at ultraslow spreading ridges,during which detachment faults were developed.This suggests that the Yarlung-Tsangpo ophiolites might represent the ocean core complexes(OCC)in the Neo-Tethys Ocean.The OCC with high topography in the seafloor were clogged in the trench and preserved as ophiolites through Indo-Eurasia collision.The clogging resulted in the demise of an old subduction and a new subduction was re-initiated beneath the clogged OCC.展开更多
We investigate the propagation of intense probe pulses in a lifetime broadened A-type three-level atomic system with a configuration of electromagnetically induced transparency. We find that ultraslow optical solitons...We investigate the propagation of intense probe pulses in a lifetime broadened A-type three-level atomic system with a configuration of electromagnetically induced transparency. We find that ultraslow optical solitons formed by a balance between dispersion and nonlinearity can be stored and retrieved in the system by switching off and on a control field. Such pulses are robust during storage and retrieval, and hence may have potential applications in optical and quantum information processing.展开更多
Without need of another control light, this paper analyses in a time-dependent way a new scheme to achieve ultraslow propagation of the input probe field through a medium composed of two-level atoms where their upper ...Without need of another control light, this paper analyses in a time-dependent way a new scheme to achieve ultraslow propagation of the input probe field through a medium composed of two-level atoms where their upper level is split into two hyperfine sub-levels via some applied static field such as a DC magnetic or a DC electric field or whatever other static field.展开更多
We investigate the shape-preserving propagation of N optical pulses in an （N ＋ 1）-level medium. We solve Maxwell-Schroedinger equations exactly and provide several types of explicit coupled soliton solutions, which...We investigate the shape-preserving propagation of N optical pulses in an （N ＋ 1）-level medium. We solve Maxwell-Schroedinger equations exactly and provide several types of explicit coupled soliton solutions, which are temporally amplitude- and group-velocity-matched multi-mode slow-optical pulses of the system.展开更多
基金Project supported by National Natural Science Foundation of China (Grant Nos. 10674060,10874043 and 10974181)by the National Basic Research Program of China (Grant Nos. 2005CB724508 and 2006CB921104)
文摘We study the ultraslow optical solitons in a resonant three-level atomic system via electromagnetically induced transparency under a density-matrix （DM） approach. The results of linear and nonlinear optical properties are compared with those obtained by using an amplitude variable （AV） approach. It is found that the results for both approaches are the same in the linear regime if the corresponding relations between the population-coherence decay rates in the DM approach and the energy-level decay rates in the AV approach are appropriately imposed. However, in the nonlinear regime there is a small difference for the self-phase modulation coefficient of the nonlinear SchrSdinger equation that governs the time evolution of probe pulse envelope. All analytical predicts are checked by numerical simulations.
基金Project supported by the National Fundamental Research Program of China (Grant No 2005CB724508)Natural Science Foundation of Jiangxi, China (Grant Nos 2007GZW0819 and 2008GQW0017)+1 种基金the Scientific Research Foundation of Jiangxi Provincial Department of Education (Grant No GJJ09504)the Foundation of Talent of Jinggang of Jiangxi Province (Grant No 2008DQ00400)
文摘This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields. This study shows that, by choosing appropriate physical parameters, self-modulation can precisely balance group velocity dispersion in the investigated system, leading to the formation of ultraslow optical solitons of the probe field. The proposed scheme may lead to the development of the controlled technique of optical buffers and optical delay lines.
基金support of the National Natural Science Foundation of China(Nos.22035008,21972155,and 21988102)the International Partnership Program of Chinese Academy of Sciences(No.1A1111KYSB20200010).
文摘Motile plant tissues can control their configurations and regulate their motion speed according to their specific requirements,which offer various protypes for biomimetic actuators with controlled motion speed.In this perspective,we focus on the speed control of plant tissues and the bioinspired strategies for speed regulation of artificial actuators.We begin with a summary to the strategies and mechanisms of motile plant tissues for controlling motion speed,ranging from ultrafast to ultraslow.We then exemplify the models for fabricating bioinspired artificial actuators and briefly discuss current application scenarios of actuators with varying speeds from ultrafast to ultraslow.Finally,we propose potential strategies for the speed regulation of actuators.
基金the National Science Fund for Distinguished Young Scholars(Grant No.42025201)。
文摘As relics of ancient ocean lithosphere,ophiolites are the most important petrological evidence for marking the sutures and also play a key role in reconstructing plate configuration.They also provide valuable windows for studying crustal accretion and mantle processes occurring at modem ocean ridges.Abundant ophiolites are distributed along the Yarlung-Tsangpo suture and represent the relics of ocean lithosphere of the Neo-Tethys.They are characterized by an incomplete litho-stratigraphy,of which the mantle section is much thicker than the crustal section.Ocean crustal rocks outcropped in the Yarlung-Tsangpo ophiolites are much thinner than normal ocean crusts(~7 km)or even absent.Tectonic settings from which the Yarlung-Tsangpo ophiolites originated remain highly controversial,although an origin of the supra-subduction zone is prevailing.Moreover,their incomplete litho-stratigraphy has been commonly attributed to tectonic dismemberment during the late-stage emplacement after their formation.Nevertheless,such an incompleteness resembles the ocean lithosphere generated at modem ultraslow spreading ridges,such as the Southwest Indian Ridge(SWIR).In this paper,we present several lines of evidence that support the formation of the Yarlung-Tsangpo ophiolites at ultraslow spreading ridges,during which detachment faults were developed.This suggests that the Yarlung-Tsangpo ophiolites might represent the ocean core complexes(OCC)in the Neo-Tethys Ocean.The OCC with high topography in the seafloor were clogged in the trench and preserved as ophiolites through Indo-Eurasia collision.The clogging resulted in the demise of an old subduction and a new subduction was re-initiated beneath the clogged OCC.
基金supported by NSF-China under Nos.11174080 and 11105052supported by the Open Fund fromthe State Key Laboratory of Precision Spectroscopy,East China Normal University
文摘We investigate the propagation of intense probe pulses in a lifetime broadened A-type three-level atomic system with a configuration of electromagnetically induced transparency. We find that ultraslow optical solitons formed by a balance between dispersion and nonlinearity can be stored and retrieved in the system by switching off and on a control field. Such pulses are robust during storage and retrieval, and hence may have potential applications in optical and quantum information processing.
基金Project supported by the Natural Science Foundation of Jiangxi Province, China （Grant No 0612006）, the Scientific Research Foundation of Jiangxi Provincial Department of Education, China （Grant No [2007]191） and by Science Foundation of East China Jiaotong University, China （Grant No 06ZKJC01）.
文摘Without need of another control light, this paper analyses in a time-dependent way a new scheme to achieve ultraslow propagation of the input probe field through a medium composed of two-level atoms where their upper level is split into two hyperfine sub-levels via some applied static field such as a DC magnetic or a DC electric field or whatever other static field.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10274021, 90403008, and 10434060, and the National Key Basic Research and Development Programme of China under Grant No 2005CB724508.
文摘We investigate the shape-preserving propagation of N optical pulses in an （N ＋ 1）-level medium. We solve Maxwell-Schroedinger equations exactly and provide several types of explicit coupled soliton solutions, which are temporally amplitude- and group-velocity-matched multi-mode slow-optical pulses of the system.
