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Journal of Physics B: Atomic, Molecular and Optical Physics - latest papers

Latest articles for Journal of Physics B: Atomic, Molecular and Optical Physics

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  • Super integrable algebraic models for electro-vibronic spectra of complex molecules
    In the present work, we provide a criterion for algebraic solvability in general fermion–boson interaction systems that conserve the total number of excitations. Relevant examples of light-matter coupled systems in molecular physics are reviewed. An analysis of achieved and avoided level crossing in super integrable and non-super integrable systems is made. Applications of this criterion are given, including the electron–phonon coupling within a carbon-based polymer. The effects of achieved crossings of energy bands are statistically studied by means of the partition function and the resulting equation of state, which are explicitly derived. Lastly, comparisons with similar integrable models in atomic physics are given, including ion traps.

  • Parametric-interference control of single- and two-photon blockade in a Jaynes–Cummings system
    Following the coupling-spanning resonance-and-interference construction introduced by Zhou et al, we use ‘universal’ only in this inherited finite-coupling sense. Here we show that the complex amplitude of a parametric drive provides direct control of this interference in a coherently driven Jaynes–Cummings (JC) system. In the weak-driving limit, imposing on the lossless one-excitation reference line gives an analytical pump condition . Over , the full steady states satisfy the adopted 1PB photon-statistics characterization. The required pump remains finite as , but the exactly decoupled cavity is Gaussian and serves only as a Gaussian-interference antibunching reference, not as JC photon blockade. At the two-excitation reference resonance, imposing while retaining gives a second analytical pump condition. Full steady-state master-equation calculations, including photon-number probabilities, identify finite parameter regions satisfying both the correlation and equal-mean Poisson criteria for two-photon blockade (2PB). A matched-Gaussian diagnostic shows that the weak-coupling end remains nearly Gaussian, whereas at stronger coupling the matched Gaussian state no longer reproduces the full . For fixed system and coherent-drive parameters, the two pump values and select steady states with 1PB and 2PB statistics. The fixed-parameter 2PB endpoint has a small two-photon probability and is not a brightness-optimized photon-pair source; at a vacuum-input extraction port, normalized output correlations equal the intracavity values.

  • In memoriam Jørgen E. Hansen
  • Two-mode hyperradiant lasing in a system of two quantum dots embedded in a bimodal photonic crystal cavity
    We propose a scheme for two-mode hyperradiant lasing in a system of two incoherently pumped semiconductor quantum dots (QDs) strongly coupled to a bimodal photonic crystal cavity. Exciton–phonon interactions are treated within a time-local polaron-transformed master equation framework, allowing us to capture both resonant and off-resonant light–matter coupling regimes. We investigate collective emission through the radiance witness (RW), mean intracavity photon numbers, and intra- and intermode second-order photon correlations. In the off-resonant regime, we show that phonon-assisted cooperative two-mode, two-photon processes significantly enhance intermode correlations and drive the system into a hyperradiant steady state, characterized by a RW exceeding the superradiant limit. By deriving Scully-Lamb-type cavity-field rate equations, we quantify the relative contributions of single-photon and two-photon emission and absorption channels and establish a direct connection between enhanced radiance and spectral linewidth narrowing. A comparison between single-mode and bimodal cavity configurations reveals that bimodal coupling leads to stronger cooperative emission and a substantial suppression of the emission linewidth. Our results highlight the constructive role of phonons in enabling cooperative multiphoton processes and demonstrate the potential of bimodal QD-cavity platforms for realizing steady-state hyperradiant light sources.

  • Ultrafast rotational Doppler effect in strong-field ionization
    Rotational Doppler effect is the angular counterpart of the linear Doppler effect: a receiver rotating in a wave field with an azimuthally varying phase can experience a shifted frequency of the wave. Here, we theoretically reveal a novel ultrafast rotational Doppler effect arising from electron motion during strong-field ionization driven by optical vortices. Using the strong-field approximation, we show that the resulting above-threshold-ionization rings in momentum space are twisted by the spiral phase of the optical vortices. The underlying mechanism is that photoelectrons emitted in different directions experience different effective frequencies of the driving laser field. The frequency shift induced by this ultrafast rotational Doppler effect depends sensitively on the position of the atoms relative to the phase singularity of the optical vortices. Our results have broad implications for investigating electron–light interactions in spatially structured strong laser fields.