422 research outputs found
The university press Redux: balancing traditional university values with a culture of digital innovation
This week the first UK conference on the state and future of university presses is taking place. The university press concept has regained strength in recent years and in the last 12 months alone a host of new presses have been launched in the UK. Anthony Cond, Director of Liverpool University Press shares his thoughts on the changing landscape of scholarly publishing, the value of bringing together perspectives from the more established presses and the new, emerging players, and new directions for the university to play a more integral role Just as presses can learn from those longer established, the established presses can learn a thing or two from the reassertion of traditional university press values by the new university presses, not least the idea of serving home institution as well as specific disciplines
The influence of a weak magnetic field in the Renormalization-Group functions of (2+1)-dimensional Dirac systems
The experimental observation of the renormalization of the Fermi velocity
as a function of doping has been a landmark for confirming the
importance of electronic interactions in graphene. Although the experiments
were performed in the presence of a perpendicular magnetic field , the
measurements are well described by a renormalization-group (RG) theory that did
not include it. Here we clarify this issue, for both massive and massless Dirac
systems, and show that for the weak magnetic fields at which the experiments
are performed, there is no change in the renormalization-group functions. Our
calculations are carried out in the framework of the Pseudo-quantum
electrodynamics (PQED) formalism, which accounts for dynamical interactions. We
include only the linear dependence in , and solve the problem using two
different parametrizations, the Feynman and the Schwinger one. We confirm the
results obtained earlier within the RG procedure and show that, within linear
order in the magnetic field, the only contribution to the renormalization of
the Fermi velocity arises due to interactions. In addition, for gapped systems,
we observe a running of the mass parameter.Comment: Discussion about the fermionic mass has been added to the previous
versio
Sedimentation stacking diagrams of binary mixtures of thick and thin hard rods
We use Onsager theory and the local density approximation to study
sedimentation-diffusion equilibrium density profiles of binary mixtures of
thick and thin hard rods. We construct stacking diagrams for three diameter
ratios, and find that even a simple spindle-shaped phase diagram with only
isotropic-nematic demixing can lead to counter-intuitive stacking sequences
such as an isotropic phase sandwiched between two nematic phases. For the most
complex phase diagram considered here, we find sixteen distinct stacking
sequences, including several with five sedimented layers. By adding
sedimentation paths to composition-pressure and density-density phase diagrams
and calculating density and composition profiles, we show that conclusions
about bulk phase diagrams of binary mixtures on the basis of
sedimentation-diffusion equilibria should be drawn warily.Comment: 9 pages, 8 figures, extended discussion in section 4, added
references, minor changes to figures (results unchanged
Tuning magnetic chirality by dipolar interactions
Chiral magnetism has gained enormous interest in recent years because of the
anticipated wealth of applications in nanoelectronics. The demonstrated
stabilization of chiral magnetic domain walls and skyrmions has been attributed
to the actively investigated Dzyaloshinskii-Moriya interaction. Recently,
however, predictions were made that suggest dipolar interactions can also
stabilize chiral domain walls and skyrmions, but direct experimental evidence
has been lacking. Here we show that dipolar interactions can indeed stabilize
chiral domain walls by directly imaging the magnetic domain walls using
scanning electron microscopy with polarization analysis. We further show that
the competition between the Dzyaloshinskii-Moriya and dipolar interactions can
reverse the domain-wall chirality. Finally, we suggest that this competition
can be tailored by a Ruderman-Kittel-Kasuya-Yosida interaction. Our work
therefore reveals that dipolar interactions play a key role in the
stabilization of chiral spin textures. This insight will open up new routes
towards balancing interactions for the stabilization of chiral magnetism
Asymmetric magnetic bubble expansion under in-plane field in Pt/Co/Pt: effect of interface engineering
We analyse the impact of growth conditions on asymmetric magnetic bubble
expansion under in-plane field in ultrathin Pt / Co / Pt films. Specifically,
using sputter deposition we vary the Ar pressure during the growth of the top
Pt layer. This induces a large change in the interfacial structure as evidenced
by a factor three change in the effective perpendicular magnetic anisotropy.
Strikingly, a discrepancy between the current theory for domain-wall
propagation based on a simple domain-wall energy density and our experimental
results is found. This calls for further theoretical development of domain-wall
creep under in-plane fields and varying structural asymmetry.Comment: 16 pages, 3 figure
Antiferromagnetic magnons as highly squeezed Fock states underlying quantum correlations
Employing the concept of two-mode squeezed states from quantum optics, we
demonstrate a revealing physical picture for the antiferromagnetic ground state
and excitations. Superimposed on a N{\'e}el ordered configuration, a spin-flip
restricted to one of the sublattices is called a sublattice-magnon. We show
that an antiferromagnetic spin-up magnon is comprised by a quantum
superposition of states with spin-up and spin-down
sublattice-magnons, and is thus an enormous excitation despite its unit net
spin. Consequently, its large sublattice-spin can amplify its coupling to other
excitations. Employing von Neumann entropy as a measure, we show that the
antiferromagnetic eigenmodes manifest a high degree of entanglement between the
two sublattices, thereby establishing antiferromagnets as reservoirs for strong
quantum correlations. Based on these novel insights, we outline strategies for
exploiting the strong quantum character of antiferromagetic (squeezed-)magnons
and give an intuitive explanation for recent experimental and theoretical
findings in antiferromagnetic magnon spintronics
New university presses in the UK: accessing a mission
In the space of just a year, five new university presses were launched in the UK. Although very different in size and stages of development, all but one were launched first and foremost as open access presses, based in or supported by their university’s library. Why should there have been such a significant flurry of activity in such a short space of time, and what can the stated objectives and activities of these presses tell us about the current UK scholarly publishing environment? To answer some of those questions, this article looks back to the original mission of the founding university presses, examines the policy and funding environments in which the new presses are operating, looks at overseas developments in recent years for comparison, and concludes with a review of the challenges these young presses face as well as the benefits all university presses, but particularly open access ones, can confer to their institutions
'Crucial time' for OA monographs
'Elitist world' discriminating against humanities must be avoided at all costs, write Martin Eve and Anthony Con
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