@article{SierraSanchezGutierrezetal.2019,
  author    = {Sierra, Miguel A. and S{\´a}nchez, David and Gutierrez, Rafael and Cuniberti, Gianaurelio and Dom{\´i}nguez-Adame, Francisco and D{\´i}az, Elena},
  title     = {Spin-polarized electron transmission in DNA-like systems},
  series = {Biomolecules},
  volume    = {10},
  journal   = {Biomolecules},
  number    = {1},
  issn      = {2218-273X},
  doi       = {10.3390/biom10010049},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193813},
  year      = {2019},
  abstract  = {The helical distribution of the electronic density in chiral molecules, such as DNA and bacteriorhodopsin, has been suggested to induce a spin-orbit coupling interaction that may lead to the so-called chirality-induced spin selectivity (CISS) effect. Key ingredients for the theoretical modelling are, in this context, the helically shaped potential of the molecule and, concomitantly, a Rashba-like spin-orbit coupling due to the appearance of a magnetic field in the electron reference frame. Symmetries of these models clearly play a crucial role in explaining the observed effect, but a thorough analysis has been largely ignored in the literature. In this work, we present a study of these symmetries and how they can be exploited to enhance chiral-induced spin selectivity in helical molecular systems.},
  language  = {en}
}
@article{GottschollWagenhoeferKlimmeretal.2022,
  author    = {Gottscholl, Andreas and Wagenh{\"o}fer, Maximilian and Klimmer, Manuel and Scherbel, Selina and Kasper, Christian and Baianov, Valentin and Astakhov, Georgy V. and Dyakonov, Vladimir and Sperlich, Andreas},
  title     = {Superradiance of spin defects in silicon carbide for maser applications},
  series = {Frontiers in Photonics},
  volume    = {3},
  journal   = {Frontiers in Photonics},
  issn      = {2673-6853},
  doi       = {10.3389/fphot.2022.886354},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284698},
  year      = {2022},
  abstract  = {Masers as telecommunication amplifiers have been known for decades, yet their application is strongly limited due to extreme operating conditions requiring vacuum techniques and cryogenic temperatures. Recently, a new generation of masers has been invented based on optically pumped spin states in pentacene and diamond. In this study, we pave the way for masers based on spin S = 3/2 silicon vacancy (V\(_{Si}\)) defects in silicon carbide (SiC) to overcome the microwave generation threshold and discuss the advantages of this highly developed spin hosting material. To achieve population inversion, we optically pump the V\(_{Si}\) into their m\(_S\) = ±1/2 spin sub-states and additionally tune the Zeeman energy splitting by applying an external magnetic field. In this way, the prerequisites for stimulated emission by means of resonant microwaves in the 10 GHz range are fulfilled. On the way to realising a maser, we were able to systematically solve a series of subtasks that improved the underlying relevant physical parameters of the SiC samples. Among others, we investigated the pump efficiency as a function of the optical excitation wavelength and the angle between the magnetic field and the defect symmetry axis in order to boost the population inversion factor, a key figure of merit for the targeted microwave oscillator. Furthermore, we developed a high-Q sapphire microwave resonator (Q ≈ 10\(^4\)-10\(^5\)) with which we find superradiant stimulated microwave emission. In summary, SiC with optimized spin defect density and thus spin relaxation rates is well on its way of becoming a suitable maser gain material with wide-ranging applications.},
  language  = {en}
}