Topology is known to stabilize rather exotic states in condensed matter and in magnetic materials. A recent example is the formation of particle-like excitations of continuous fields, as predicted by Skyrme. These so called skyrmions occur in presence of inversion symmetry breaking and indirect exchange, both favouring chiral magnetic structures via the Dzyaloshinskii-Moriya Interaction (DMI)...
In recent times, the interaction between magnetization and heat currents in a magnetic material has gained a renewed interest thanks to the observation of the spin Seebeck effect (SSE) [1,2]. The SSE is the spin counterpart of the Seebeck effect that corresponds to the generation of a pure magnetization current in a magnetic insulator as consequence of a thermal gradient. This is electrically...
Spectroscopy in the femtosecond time domain can both reveal fundamental insight in the properties of
materials and provide relevant experimental tests for functional systems. The quest for sources of
ultrashort photon pulses (~100 fs) in the Extreme Ultraviolet (EUV) region operating with an adjustable
repetition rate up to the MHz range has led, in this last years, to the development of high...
Rare-earth orthoferrites (RFeO3) have been intensively studied in last years, as they exhibit a variety of interesting physical properties, with a large number of works having addressed the underlying microscopic mechanisms [1]. The rare-earth size drives the cooperative rotations of the FeO6 octahedra, which is known to linearly scale with the octahedra tilt angles [1]. Their physics has been...
Bi2Fe4O9 is a common by-product in the synthesis of the multiferroic compound BiFeO3 and has been claimed itself to display multiferroic properties [1]. The lattice formed by the two different sites of four iron Fe3+ magnetic atoms is quite remarkable as it materializes the first analogue of a magnetic pentagonal lattice [2]. For its peculiar lattice geometry it has attracted interest in the...
Many biophysical factors affect human circulation, so that a satisfactory understanding of its behavior is challenging [1]. Moreover, congenital vascular disease is the leading cause of pediatric death, and it is proven that physiological parameters such as cardiac output, cerebral blood flow, and arterial stiffness are related to age [2]. For these reasons, the assessment of cardiovascular...
The electron accelerator MAMI is multilevel racetrack microtron with a beam energy from 180 MeV up to 1.6 GeV and a continiuous beam current of more than 20 µA. The excellent beam quality due to the low emittance in transveral and longitudinal direction is well suited for channeling experiments and related radiation investigations.
The possibility to produce undulator-like radiation in the...
Despite the large strength of the coherent effects of particle deflection and radiation in crystals, all their applications are essentially limited by the incoherent scattering process. Though the difference of the latter from the scattering process in amorphous media was, in fact, envisaged by both the x-ray diffraction and coherent bremsstrahlung theories, the relational effect of multiple...
Cerenkov counters and transition radiation detectors are particle identification detectors (PID) used in many HEP experiments [1, 2]. Study and development of new accelerator facilities such as Future Circular Colliders (CERN), NICA (JINR) and others formulate new needs for particle identification in conditions of very high energies and luminosities. Parametric x-rays (PXR) [3] have big...
A unique program of measurements of electric and magnetic dipole moments of unstable
particles at the LHC, based on the phenomenon of spin precession of channeled particles in
bent crystals, is presented [1, 2]. The ongoing R&D, feasibility studies, and the physics reach
for the proposed experiment based on the LHCb detector are discussed, along with future
perspectives for the tau lepton...
Twenty years ago at CERN it was demonstrated that the strong crystalline field of a single-element crystal, e.g. Si or W, may lead to a huge decrease in the shower length, if the beam direction is aligned with the crystal axes. Recently, we extended these studies to high-Z scintillator crystals typically exploited in electromagneticcalorimeters used in HEP and astrophysics. In particular, we...