Rabi oscillation is an elementary laser-driven physical process in atoms and artificial atoms from solid-state systems,while it is rarely demonstrated in molecules.Here,we investigate the bond-length-dependent Rabi os...Rabi oscillation is an elementary laser-driven physical process in atoms and artificial atoms from solid-state systems,while it is rarely demonstrated in molecules.Here,we investigate the bond-length-dependent Rabi oscillations with varying Rabi frequencies in strong-laser-field dissociation of H2+.The coupling of the bond stretching and Rabi oscillations makes the nuclei gain different kinetic energies while the electron is alternatively absorbing and emitting photons.The resulting proton kinetic energy spectra show rich structures beyond the prediction of the Floquet theorem and the well-accepted resonant one-photon dissociation pathway.Our study shows that the laser-driven Rabi oscillations accompanied by nuclear motions are essential to understanding the bond-breaking mechanism and provide a time-resolved perspective to manipulate rich dynamics of the strong-laser-field dissociation of molecules.展开更多
More than ten years ago,the observation of the low-energy structure in the photoelectron energy spectrum,regarded as an“ionization surprise,”has overthrown our understanding of strong-field physics.However,the simil...More than ten years ago,the observation of the low-energy structure in the photoelectron energy spectrum,regarded as an“ionization surprise,”has overthrown our understanding of strong-field physics.However,the similar low-energy nuclear fragment generation from dissociating molecules upon the photon energy absorption,one of the well-observed phenomena in light-molecule interaction,still lacks an unambiguous mechanism and remains mysterious.Here,we introduce a time-energy-resolved manner using a multicycle near-infrared femtosecond laser pulse to identify the physical origin of the light-induced ultrafast dynamics of molecules.By simultaneously measuring the bond-stretching times and photon numbers involved in the dissociation of H_(2)^(+) driven by a polarization-skewed laser pulse,we reveal that the low-energy protons(below 0.7 eV)are produced via dipole-transitions at large bond lengths.The observed low-energy protons originate from strong-field dissociation of high vibrational states rather than the low ones of H_(2)^(+) cation,which is distinct from the well-accepted bond-softening picture.Further numerical simulation of the time-dependent Schrödinger equation unveils that the electronic states are periodically distorted by the strong laser field,and the energy gap between the field-dressed transient electronic states may favor the one-or three-photon transitions at the internuclear distance larger than 5 a.u.The time-dependent scenario and our time-energy-resolved approach presented here can be extended to other molecules to understand the complex ultrafast dynamics.展开更多
Comprehension of photon-triggered molecular processes is essential in the study of various important topics in physics,chemistry,and biology.Here we propose a correlated tunneling picture to understand the dissociativ...Comprehension of photon-triggered molecular processes is essential in the study of various important topics in physics,chemistry,and biology.Here we propose a correlated tunneling picture to understand the dissociative ionization process of molecules in intense laser fields based on a quantum model developed in the framework of many-body S-matrix theory including nuclear vibrational motion.In this quantum correlation picture,the single ionization of H_(2)and the subsequent electron-ion recollisioninduced dissociation are considered as an entangled correlated process.It enables us to attribute the interference pattern in the joint-energy spectra to combined effects of single-slit diffraction and multi-slit interference of correlated electron-nuclear wave packets in the time domain.Our work opens a new avenue to understanding molecular dissociative ionization processes in external fields.展开更多
基金This work was supported by the National Key R&D Program of China(Grants Nos.2018YFA0306303 and 2018YFA0404802)the National Natural Science Fund(Grants Nos.11834004,11925405,12241407,12227807 and 91850203)+1 种基金Innovation Program of Shanghai Municipal Education Commission(Grant No.2017-01-07-00-02-E00034)S.P.acknowledges the support from the Academic Innovation Ability Enhancement Program for Excellent Doctoral Students of East China Normal University in 2021(Grant No.40600-30302-515100/141).
文摘Rabi oscillation is an elementary laser-driven physical process in atoms and artificial atoms from solid-state systems,while it is rarely demonstrated in molecules.Here,we investigate the bond-length-dependent Rabi oscillations with varying Rabi frequencies in strong-laser-field dissociation of H2+.The coupling of the bond stretching and Rabi oscillations makes the nuclei gain different kinetic energies while the electron is alternatively absorbing and emitting photons.The resulting proton kinetic energy spectra show rich structures beyond the prediction of the Floquet theorem and the well-accepted resonant one-photon dissociation pathway.Our study shows that the laser-driven Rabi oscillations accompanied by nuclear motions are essential to understanding the bond-breaking mechanism and provide a time-resolved perspective to manipulate rich dynamics of the strong-laser-field dissociation of molecules.
基金supported by the National Key R&D Program of China(Grant Nos.2018YFA0306303,2018YFA0404802)the National Natural Science Fund(Grant Nos.11834004,11621404,11925405,91850203)+3 种基金the 111 Project of China(Grant No.B12024)Projects from Shanghai Science and Technology Commission(Grant No.19JC1412200)the Innovation Program of Shanghai Municipal Education Commission(Grant No.2017-01-07-00-02-E00034)S.Pan acknowledges the support from the Academic Innovation Ability Enhancement Program for Excellent Doctoral Students of East China Normal University in 2021(Grant No.40600-30302-515100/141).
文摘More than ten years ago,the observation of the low-energy structure in the photoelectron energy spectrum,regarded as an“ionization surprise,”has overthrown our understanding of strong-field physics.However,the similar low-energy nuclear fragment generation from dissociating molecules upon the photon energy absorption,one of the well-observed phenomena in light-molecule interaction,still lacks an unambiguous mechanism and remains mysterious.Here,we introduce a time-energy-resolved manner using a multicycle near-infrared femtosecond laser pulse to identify the physical origin of the light-induced ultrafast dynamics of molecules.By simultaneously measuring the bond-stretching times and photon numbers involved in the dissociation of H_(2)^(+) driven by a polarization-skewed laser pulse,we reveal that the low-energy protons(below 0.7 eV)are produced via dipole-transitions at large bond lengths.The observed low-energy protons originate from strong-field dissociation of high vibrational states rather than the low ones of H_(2)^(+) cation,which is distinct from the well-accepted bond-softening picture.Further numerical simulation of the time-dependent Schrödinger equation unveils that the electronic states are periodically distorted by the strong laser field,and the energy gap between the field-dressed transient electronic states may favor the one-or three-photon transitions at the internuclear distance larger than 5 a.u.The time-dependent scenario and our time-energy-resolved approach presented here can be extended to other molecules to understand the complex ultrafast dynamics.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0307700)the National Natural Science Foundation of China(Grant Nos.12274273,12304379,11925405+2 种基金12304304)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302101)the Natural and Science Foundation of Top Talent of SZTU(Grant No.GDRC202202)。
文摘Comprehension of photon-triggered molecular processes is essential in the study of various important topics in physics,chemistry,and biology.Here we propose a correlated tunneling picture to understand the dissociative ionization process of molecules in intense laser fields based on a quantum model developed in the framework of many-body S-matrix theory including nuclear vibrational motion.In this quantum correlation picture,the single ionization of H_(2)and the subsequent electron-ion recollisioninduced dissociation are considered as an entangled correlated process.It enables us to attribute the interference pattern in the joint-energy spectra to combined effects of single-slit diffraction and multi-slit interference of correlated electron-nuclear wave packets in the time domain.Our work opens a new avenue to understanding molecular dissociative ionization processes in external fields.