7,573 research outputs found
Joint superexchange--Jahn-Teller mechanism for A-type antiferromagnetism in
We propose a mechanism for A-type antiferromagnetism in orthorombic LaMnO_3,
compatible with the large Jahn-Teller splitting inferred from structural data.
Orbital ordering resulting from Jahn-Teller distortions effectively leads to
A-type ordering (antiferromagnetic in the c axis and ferromagnetic in the ab
plane) provided the in-plane distorsion Q_2 is large enough, a condition
generally fulfilled in existing data.Comment: 4 pages Late
The Consequences of Polyandry for Sibship Structures, Distributions of Relationships and Relatedness, and Potential for Inbreeding in a Wild Population
We thank the Tsawout and Tseycum First Nations for access to Mandarte Island, Pirmin Nietlisbach, Lukas Keller, Greta Bocedi, Brad Duthie, and Matthew Wolak for helpful discussions, and the European Research Council, National Sciences and Engineering Research Council of Canada, and Swiss National Science Foundation for funding. Field data collected following UBC Animal Care Committee (A07-0309) and Environment Canada (Master banding permit 10596) guidelines.Peer reviewedPublisher PD
DPA on quasi delay insensitive asynchronous circuits: formalization and improvement
The purpose of this paper is to formally specify a flow devoted to the design
of Differential Power Analysis (DPA) resistant QDI asynchronous circuits. The
paper first proposes a formal modeling of the electrical signature of QDI
asynchronous circuits. The DPA is then applied to the formal model in order to
identify the source of leakage of this type of circuits. Finally, a complete
design flow is specified to minimize the information leakage. The relevancy and
efficiency of the approach is demonstrated using the design of an AES
crypto-processor.Comment: Submitted on behalf of EDAA (http://www.edaa.com/
Binding energy of localized biexcitons in quantum wells
A variational calculation of the ground state energy of a biexciton in a
GaAs/AlGaAs quantum well is presented. The well width fluctuations leading to
trapping of the biexcitons are modeled by a parabolic potential. The results
obtained for different well widths are compared with recent experimental data.
Good agreement is obtained both for the biexciton binding energy and for the
Haynes factor. We find that the structure of a biexciton is similar to the one
of the H_2 molecule.Comment: 9 pages, 4 figure
Evolution of precopulatory and post-copulatory strategies of inbreeding avoidance and associated polyandry
Acknowledgments This work was funded by a European Research Council Starting Grant to JMR. Computer simulations were performed using the Maxwell Computing Cluster at the University of Aberdeen. We thank Matthew E. Wolak and two anonymous reviewers for very helpful comments.Peer reviewedPublisher PD
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