We studied time-dependent features of high-frequency fluorescent radiation from a two-level quantum system with broken inversion spatial symmetry. The system in question was modelled after a one-electron two-level asymmetric polar semiconductor quantum dot whose electric dipole moment operator has permanent unequal diagonal matrix elements. The dot was permanently excited by incoherent pumping of some sort. Our attention was focused on the evolution of the fluorescence spectrum following abrupt switching on of an additional driving monochromatic field, which frequency is much lower than the optical transition frequency of the quantum dot. An analytical expression for the fluorescence spectrum as a function of the amplitude, initial phase and frequency of the monochromatic driving field, as well as of the pumping intensity and the elapsed time, was derived.We studied time-dependent features of high-frequency fluorescent radiation from a two-level quantum system with broken inversion spatial symmetry. The system in question was modelled after a one-electron two-level asymmetric polar semiconductor quantum dot whose electric dipole moment operator has permanent unequal diagonal matrix elements. The dot was permanently excited by incoherent pumping of some sort. Our attention was focused on the evolution of the fluorescence spectrum following abrupt switching on of an additional driving monochromatic field, which frequency is much lower than the optical transition frequency of the quantum dot. An analytical expression for the fluorescence spectrum as a function of the amplitude, initial phase and frequency of the monochromatic driving field, as well as of the pumping intensity and the elapsed time, was derived.

arXiv:2412.11249Dec 15, 20240 citations

Hanle fluorescence spectra of an atom with a Jg =0⇆ Je =1 transition

Peng Zhou, S. Swain

We have investigated the two basic types of Hanle fluorescence spectra, distinguished by the direction of observation, from a V-type atom with a ${\mathrm{J}}_{\mathrm{g}}$ =0\ensuremath{\leftrightarrows} ${\mathrm{J}}_{\mathrm{e}}$ =1 transition excited by a linearly polarized laser. In the absence of a magnetic field to lift the Zeeman degeneracy of the sublevels, the incoherent fluorescence spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$ (\ensuremath{\omega}) is dark for all Rabi frequencies, while the incoherent fluorescence spectrum ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$ (\ensuremath{\omega}) exhibits a single peak for small Rabi frequencies and a Mollow-like triplet for large Rabi frequencies. However, if a magnetic field is applied, the incoherent spectra are composed, in general, of five peaks. When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\ll}\ensuremath{\Omega}, the incoherent spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$ (\ensuremath{\omega}) has four peaks, while ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$ (\ensuremath{\omega}) has a Mollow-like triplet, and the integrated area (i.e., the fluorescence intensity) under the spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$ (\ensuremath{\omega}) is much less than that of ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$ (\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\gg}:\ensuremath{\Omega}, both incoherent spectra have a two-peak structure similar to that of a two-level atom far off resonance, but the integrated area under the spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$ (\ensuremath{\omega}) is much greater than that of ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$ (\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ =\ensuremath{\Omega}\ensuremath{\gg}:\ensuremath{\gamma}, both spectra have a similar five-peak structure, and the same integrated area. The results obtained are interpreted in the dressed atomic state representation. In the strong-field limit, the secular approximation is invoked, and analytical expressions of the resonance fluorescence spectra are derived which demonstrate the dependence of the peak heights and widths of the resonance fluorescence spectra on the intensities of the magnetic and linear polarized laser fields in a more transparent way.We have investigated the two basic types of Hanle fluorescence spectra, distinguished by the direction of observation, from a V-type atom with a ${\mathrm{J}}_{\mathrm{g}}$ =0\ensuremath{\leftrightarrows}${\mathrm{J}}_{\mathrm{e}}$ =1 transition excited by a linearly polarized laser. In the absence of a magnetic field to lift the Zeeman degeneracy of the sublevels, the incoherent fluorescence spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$(\ensuremath{\omega}) is dark for all Rabi frequencies, while the incoherent fluorescence spectrum ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$(\ensuremath{\omega}) exhibits a single peak for small Rabi frequencies and a Mollow-like triplet for large Rabi frequencies. However, if a magnetic field is applied, the incoherent spectra are composed, in general, of five peaks. When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\ll}\ensuremath{\Omega}, the incoherent spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$(\ensuremath{\omega}) has four peaks, while ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$(\ensuremath{\omega}) has a Mollow-like triplet, and the integrated area (i.e., the fluorescence intensity) under the spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$(\ensuremath{\omega}) is much less than that of ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\gg}:\ensuremath{\Omega}, both incoherent spectra have a two-peak structure similar to that of a two-level atom far off resonance, but the integrated area under the spectrum ${\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}$(\ensuremath{\omega}) is much greater than that of ${\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}$(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ =\ensuremath{\Omega}\ensuremath{\gg}:\ensuremath{\gamma}, both spectra have a similar five-peak structure, and the same integrated area. The results obtained are interpreted in the dressed atomic state representation. In the strong-field limit, the secular approximation is invoked, and analytical expressions of the resonance fluorescence spectra are derived which demonstrate the dependence of the peak heights and widths of the resonance fluorescence spectra on the intensities of the magnetic and linear polarized laser fields in a more transparent way.

Physical Review AJan 1, 19971 citation

Polarization of fluorescence produced by transitions from upper excited levels

I. E. Zalesskii, V. N. Kotlo, A. N. Sevchenko +2 more

Soviet physics. DokladyMar 1, 19750 citations

Fluorescence of incoherently pumped open polar quantum system driven by a nonresonant pulse

Andrey Vladimirovich Soldatov

Abstract The process of high-frequency fluorescence of a two-level open quantum system with permanent electric dipole moment interacting with a pulse of nonresonant monochromatic electromagnetic (laser) field is modeled and studied by methods of nonequilibrium quantum statistical mechanics. The system in question is represented by a one-electron two-level asymmetric polar semiconductor quantum dot characterized by the electric dipole moment operator with unequal diagonal matrix elements in its ground and excited quantum states, and interacting with dissipative environment. The dot is permanently excited by incoherent pumping and is driven by an amplitude modulated pulse, whose monochromatic carrier frequency is much lower than the optical transition frequency of the quantum dot. We derive an analytical expression for the time-dependent fluorescence power spectrum as a function of the amplitude, duration, initial phase, and carrier frequency of the rectangular monochromatic driving pulse, as well as of the pumping intensity and observation time. We show that the pulse itself does not add any discernable amount of energy to the fluorescence intensity but rather facilitates redistribution of the energy incoherently pumped into the system over a plurality of spectral peaks that arise under the influence of the pulse instead of the initial stationary single-peaked fluorescence spectrum observed before the arrival of the pulse and after its departure.Abstract The process of high-frequency fluorescence of a two-level open quantum system with permanent electric dipole moment interacting with a pulse of nonresonant monochromatic electromagnetic (laser) field is modeled and studied by methods of nonequilibrium quantum statistical mechanics. The system in question is represented by a one-electron two-level asymmetric polar semiconductor quantum dot characterized by the electric dipole moment operator with unequal diagonal matrix elements in its ground and excited quantum states, and interacting with dissipative environment. The dot is permanently excited by incoherent pumping and is driven by an amplitude modulated pulse, whose monochromatic carrier frequency is much lower than the optical transition frequency of the quantum dot. We derive an analytical expression for the time-dependent fluorescence power spectrum as a function of the amplitude, duration, initial phase, and carrier frequency of the rectangular monochromatic driving pulse, as well as of the pumping intensity and observation time. We show that the pulse itself does not add any discernable amount of energy to the fluorescence intensity but rather facilitates redistribution of the energy incoherently pumped into the system over a plurality of spectral peaks that arise under the influence of the pulse instead of the initial stationary single-peaked fluorescence spectrum observed before the arrival of the pulse and after its departure.

Theoretical and Mathematical PhysicsDec 1, 20250 citations

We have investigated the two basic types of Hanle fluorescence spectra, distinguished by the direction of observation, from a V-type atom with a

{\mathrm{J}}_{\mathrm{g}}

=0\ensuremath{\leftrightarrows}

{\mathrm{J}}_{\mathrm{e}}

=1 transition excited by a linearly polarized laser. In the absence of a magnetic field to lift the Zeeman degeneracy of the sublevels, the incoherent fluorescence spectrum

{\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}

(\ensuremath{\omega}) is dark for all Rabi frequencies, while the incoherent fluorescence spectrum

{\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}

(\ensuremath{\omega}) exhibits a single peak for small Rabi frequencies and a Mollow-like triplet for large Rabi frequencies. However, if a magnetic field is applied, the incoherent spectra are composed, in general, of five peaks. When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\ll}\ensuremath{\Omega}, the incoherent spectrum

{\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}

(\ensuremath{\omega}) has four peaks, while

{\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}

(\ensuremath{\omega}) has a Mollow-like triplet, and the integrated area (i.e., the fluorescence intensity) under the spectrum

{\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}

(\ensuremath{\omega}) is much less than that of

{\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}

(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\gg}:\ensuremath{\Omega}, both incoherent spectra have a two-peak structure similar to that of a two-level atom far off resonance, but the integrated area under the spectrum

{\mathrm{G}}_{\mathrm{X}}^{\mathrm{inc}}

(\ensuremath{\omega}) is much greater than that of

{\mathrm{G}}_{\mathrm{Y}}^{\mathrm{inc}}

(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ =\ensuremath{\Omega}\ensuremath{\gg}:\ensuremath{\gamma}, both spectra have a similar five-peak structure, and the same integrated area. The results obtained are interpreted in the dressed atomic state representation. In the strong-field limit, the secular approximation is invoked, and analytical expressions of the resonance fluorescence spectra are derived which demonstrate the dependence of the peak heights and widths of the resonance fluorescence spectra on the intensities of the magnetic and linear polarized laser fields in a more transparent way.