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To reproduce the experimental splittings, we developed a numerical 1D model to solve the rovibrational problem. In this work, we apply the model using the dihedral angle between the planes defined by (i) the C(phen)—OH group and (ii) the phenyl ring as the leading coordinate. This represents a periodic intramolecular motion, whose periodicity is influenced by the identities and positions of the substituents on the phenyl ring.

Magnetic molecules have been proposed as versatile building blocks for quantum computing and molecular spintronics devices. The molecular spin can be used to encode quantum information in qubits or even perform logic operations as quantum gates with unmatched reproducibility and scalability. In spintronics, that same molecular spin can be used to generate spin currents in molecular based spin filters, spin switches or spin valves in carbon-nanotube/molecule hybrids, among other applications. Several strategies have been followed to couple the magnetic molecules to carbon nanotubes: direct physisorption of the molecules, covalent bonding or encapsulation of the magnetic molecules. We have developed the synthesis of mechanically interlocked rotaxane-like SWCNT derivatives (MINTs), in which the ring-closing metathesis of a U-shape molecule around SWCNTs is templated. In particular, we fabricated Cu2+ and Co2+ metalloporphyrin dimer rings mechanically interlocked around carbon nanotubes to form magnetic MINTs (mMINT). Magnetic porphyrins are selected due to their recently proved suitability as qubits, even preserving their magnetic properties and quantum coherence on surfaces. The mechanical bond places the porphyrin magnetic cores in close contact with the SWCNT without disturbing the molecular spin nor the carbon nanotube structure. The magnetic properties of the metallic dimers are preserved upon formation the mechanically interlocked hybrid.

Recent developments in attosecond technology led to table-top x-ray spectroscopy in the soft x-ray range, thus uniting the element- and state-specificity of core-level x-ray absorption spectroscopy with the time resolution to follow electronic dynamics in real-time. We describe recent work in attosecond technology and investigations into materials such as Si, SiO2, GaN, Al2O3, Ti, and TiO2, enabled by the convergence of these two capabilities. We showcase the state-of-the-art on isolated attosecond soft x-ray pulses for x-ray absorption near-edge spectroscopy to observe the 3d-state dynamics of the semi-metal TiS2 with attosecond resolution at the Ti L-edge (460 eV). We describe how the element- and state-specificity at the transition metal L-edge of the quantum material allows us to unambiguously identify how and where the optical field influences charge carriers. This precision elucidates that the Ti:3d conduction band states are efficiently photo-doped to a density of 1.9 × 1021 cm−3. The light-field induces coherent motion of intra-band carriers across 38% of the first Brillouin zone. Lastly, we describe the prospects with such unambiguous real-time observation of carrier dynamics in specific bonding or anti-bonding states and speculate that such capability will bring unprecedented opportunities toward an engineered approach for designer materials with pre-defined properties and efficiency. Examples are composites of semiconductors and insulators like Si, Ge, SiO2, GaN, BN, and quantum materials like graphene, transition metal dichalcogens, or high-Tc superconductors like NbN or LaBaCuO. Exiting are prospects to scrutinize canonical questions in multi-body physics, such as whether the electrons or lattice trigger phase transitions., Peer Reviewed, Postprint (published version)

The fundamental polarization singularities of monochromatic light are normally associated with invariance under coordinated rotations: symmetry operations that rotate the spatial dependence of an electromagnetic field by an angle and its polarization by a multiple of that angle. These symmetries are generated by mixed angular momenta of the form J_γ = L + γ S, and they generally induce Möbius-strip topologies, with the coordination parameter restricted to integer and half-integer values. In this work we construct beams of light that are invariant under coordinated rotations for arbitrary rational γ, by exploiting the higher internal symmetry of ‘bicircular’ superpositions of counter-rotating circularly polarized beams at different frequencies. We show that these beams have the topology of a torus knot, which reflects the subgroup generated by the torus-knot angular momentum J_γ, and we characterize the resulting optical polarization singularity using third-and higher-order field moment tensors, which we experimentally observe using nonlinear polarization tomography., Peer Reviewed, Postprint (author's final draft)

The fundamental polarization singularities of monochromatic light are normally associated with invariance under coordinated rotations: symmetry operations that rotate the spatial dependence of an electromagnetic field by an angle ¿ and its polarization by a multiple ¿¿ of that angle. These symmetries are generated by mixed angular momenta of the form J¿¿=¿L¿+¿¿S, and they generally induce Möbius-strip topologies, with the coordination parameter ¿ restricted to integer and half-integer values. In this work we construct beams of light that are invariant under coordinated rotations for arbitrary rational ¿, by exploiting the higher internal symmetry of ‘bicircular’ superpositions of counter-rotating circularly polarized beams at different frequencies. We show that these beams have the topology of a torus knot, which reflects the subgroup generated by the torus-knot angular momentum J¿, and we characterize the resulting optical polarization singularity using third- and higher-order field moment tensors, which we experimentally observe using nonlinear polarization tomography., Peer Reviewed, Postprint (author's final draft)

This paper has been prepared by the Symphony collaboration (University of Warsaw, Uniwersytet Jagielloński, DESY/CNR and ICFO) on the occasion of the 25th anniversary of the ‘simple man’s models’ which underlie most of the phenomena that occur when intense ultrashort laser pulses interact with matter. The phenomena in question include high-harmonic generation (HHG), above-threshold ionization (ATI), and non-sequential multielectron ionization (NSMI). ‘Simple man’s models’ provide both an intuitive basis for understanding the numerical solutions of the time-dependent Schrödinger equation and the motivation for the powerful analytic approximations generally known as the strong field approximation (SFA). In this paper we first review the SFA in the form developed by us in the last 25 years. In this approach the SFA is a method to solve the TDSE, in which the non-perturbative interactions are described by including continuum–continuum interactions in a systematic perturbation-like theory. In this review we focus on recent applications of the SFA to HHG, ATI and NSMI from multi-electron atoms and from multi-atom molecules. The main novel part of the presented theory concerns generalizations of the SFA to: (i) time-dependent treatment of two-electron atoms, allowing for studies of an interplay between electron impact ionization and resonant excitation with subsequent ionization; (ii) time-dependent treatment in the single active electron approximation of ‘large’ molecules and targets which are themselves undergoing dynamics during the HHG or ATI processes. In particular, we formulate the general expressions for the case of arbitrary molecules, combining input from quantum chemistry and quantum dynamics. We formulate also theory of time-dependent separable molecular potentials to model analytically the dynamics of realistic electronic wave packets for molecules in strong laser fields., Peer Reviewed, Postprint (author's final draft)