@article{13998,
  abstract     = {The interaction of strong near-infrared (NIR) laser pulses with wide-bandgap dielectrics produces high harmonics in the extreme ultraviolet (XUV) wavelength range. These observations have opened up the possibility of attosecond metrology in solids, which would benefit from a precise measurement of the emission times of individual harmonics with respect to the NIR laser field. Here we show that, when high-harmonics are detected from the input surface of a magnesium oxide crystal, a bichromatic probing of the XUV emission shows a clear synchronization largely consistent with a semiclassical model of electron–hole recollisions in bulk solids. On the other hand, the bichromatic spectrogram of harmonics originating from the exit surface of the 200 μm-thick crystal is strongly modified, indicating the influence of laser field distortions during propagation. Our tracking of sub-cycle electron and hole re-collisions at XUV energies is relevant to the development of solid-state sources of attosecond pulses.},
  author       = {Vampa, Giulio and Lu, Jian and You, Yong Sing and Baykusheva, Denitsa Rangelova and Wu, Mengxi and Liu, Hanzhe and Schafer, Kenneth J and Gaarde, Mette B and Reis, David A and Ghimire, Shambhu},
  issn         = {1361-6455},
  journal      = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  keywords     = {Condensed Matter Physics, Atomic and Molecular Physics, and Optics},
  number       = {14},
  publisher    = {IOP Publishing},
  title        = {{Attosecond synchronization of extreme ultraviolet high harmonics from crystals}},
  doi          = {10.1088/1361-6455/ab8e56},
  volume       = {53},
  year         = {2020},
}

@article{14007,
  abstract     = {In a recent article by Hockett et al (2016 J. Phys. B: At. Mol. Opt. Phys. 49 095602), time delays arising in the context of molecular single-photon ionization are investigated from a theoretical point of view. We argue that one of the central equations given in this article is incorrect and present a reformulation that is consistent with the established treatment of angle-dependent scattering delays (Eisenbud 1948 PhD Thesis Princeton University; Wigner 1955 Phys. Rev. 98 145–7; Smith 1960 Phys. Rev. 118 349–6; Nussenzveig 1972 Phys. Rev. D 6 1534–42).},
  author       = {Baykusheva, Denitsa Rangelova and Wörner, Hans Jakob},
  issn         = {1361-6455},
  journal      = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  keywords     = {Condensed Matter Physics, Atomic and Molecular Physics, and Optics},
  number       = {7},
  publisher    = {IOP Publishing},
  title        = {{Comment on ‘Time delays in molecular photoionization’}},
  doi          = {10.1088/1361-6455/aa62b5},
  volume       = {50},
  year         = {2017},
}

@article{14021,
  abstract     = {We present the detailed analysis of a new two-pulse orientation scheme that achieves macroscopic field-free orientation at the high particle densities required for attosecond and high-harmonic spectroscopies (Kraus et al 2013 arXiv:1311.3923). Carbon monoxide molecules are oriented by combining one-colour and delayed two-colour non-resonant femtosecond laser pulses. High-harmonic generation is used to probe the oriented wave-packet dynamics and reveals that a very high degree of orientation (Nup/Ntotal = 0.73–0.82) is achieved. We further extend this approach to orienting carbonyl sulphide molecules. We show that the present two-pulse scheme selectively enhances orientation created by the hyperpolarizability interaction whereas the ionization-depletion mechanism plays no role. We further control and optimize orientation through the delay between the one- and two-colour pump pulses. Finally, we demonstrate a complementary encoding of electronic-structure features, such as shape resonances, in the even- and odd-harmonic spectrum. The achieved progress makes two-pulse field-free orientation an attractive tool for a broad class of time-resolved measurements.},
  author       = {Kraus, P M and Baykusheva, Denitsa Rangelova and Wörner, H J},
  issn         = {1361-6455},
  journal      = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  keywords     = {Condensed Matter Physics, Atomic and Molecular Physics, and Optics},
  number       = {12},
  publisher    = {IOP Publishing},
  title        = {{Two-pulse orientation dynamics and high-harmonic spectroscopy of strongly-oriented molecules}},
  doi          = {10.1088/0953-4075/47/12/124030},
  volume       = {47},
  year         = {2014},
}

@article{576,
  abstract     = {We study the free expansion of a pancake-shaped Bose-condensed gas, which is initially trapped under harmonic confinement and containing a vortex at its centre. In the case of a radial expansion holding the axial confinement fixed we consider various models for the interactions, depending on the thickness of the condensate relative to the value of the scattering length. We are thus able to evaluate different scattering regimes ranging from quasi-three-dimensional (Q3D) to strictly two-dimensional (2D). We find that as the system goes from Q3D to 2D the expansion rate of the condensate increases whereas that of the vortex core decreases. In the Q3D scattering regime we also examine a fully free expansion in 3D and find oscillatory behaviour for the vortex core radius: an initial fast expansion of the vortex core is followed by a slowing down. Such a nonuniform expansion rate of the vortex core implies that the timing of its observation should be chosen appropriately.},
  author       = {Hosten, Onur and Vignolo, Patrizia and Minguzzi, Anna and Tanatar, Bilal and Tosi, Mario},
  issn         = {1361-6455},
  journal      = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  number       = {12},
  publisher    = {IOP Publishing },
  title        = {{Free expansion of two-dimensional condensates with a vortex}},
  doi          = {10.1088/0953-4075/36/12/306},
  volume       = {36},
  year         = {2003},
}