Two-particle Kapitza-Dirac diffraction

We extend the study of Kapitza-Dirac diffraction to the case of two-particle systems. Due to the exchange effects the shape and visibility of the two-particle detection patterns show important differences for identical and distinguishable particles. We also identify a novel quantum statistics effect present in momentum space for some values of the initial particle momenta, which is associated with different numbers of photon absorptions compatible with the final momenta.Comment: Minor changes with the published versio

The role of pressure on the magnetism of bilayer graphene

We study the effect of pressure on the localized magnetic moments induced by vacancies in bilayer graphene in the presence of topological defects breaking the bipartite nature of the lattice. By using a mean-field Hubbard model we address the two inequivalent types of vacancies that appear in the Bernal stacking bilayer graphene. We find that by applying pressure in the direction perpendicular to the layers the critical value of the Hubbard interaction needed to polarize the system decreases. The effect is particularly enhanced for one type of vacancies, and admits straightforward generalization to multilayer graphene in Bernal stacking and graphite. The present results clearly demonstrate that the magnetic behavior of multilayer graphene can be affected by mechanical transverse deformation

Compositeness effects, Pauli's principle and entanglement

We analyse some compositeness effects and their relation with entanglement. We show that the purity of a composite system increases, in the sense of the expectation values of the deviation operators, with large values of the entanglement between the components of the system. We also study the validity of Pauli's principle in composite systems. It is valid within the limits of application of the approach presented here. We also present an example of two identical fermions, one of them entangled with a distinguishable particle, where the exclusion principle cannot be applied. This result can be important in the description of open systems

Anatomía descriptiva y funcional del ligamento cruzado anterior: implicaciones clínico-quirúrgicas

El ligamento cruzado anterior (LCA) es una estructura anatómica vital para la estabilidad de la rodilla y su correcta plastias exige que su tensión, dirección y punto ble al LCA original. Este trabajo intenta actualizar los aspectos anatómicos y funcionales fundamentales para una correcta cirugía de las lesiones del LCA.The anterior cruciate ligament (ACL) is a vital structure for stability of the knee and its correct biomechanics. ACL repair by means of grafts requires that tension, direction and attachment points resemble those of original ligament. This work attempts to update the fundamental functional and anatomical aspects for correct surgery of ACL

Elección del implante intraarticular en el tratamiento de las lesiones del ligamento cruzado anterior

Los autores hacen una revisión de los diferentes implantes usados para la sustitución intraarticular del ligamento cruzado anterior (LCA). Se analizan los injertos autólogos, los materiales sintéticos y los aloinjertos tendinosos. Nos encontramos ante un tema sujeto a controversia, aunque la tendencia actual es el uso de autoinjertos de hueso -tendón rotuliano- hueso. No obstante, ninguno de los tejidos sustitutivos puede remedar por completo la anatomía del LCA original.The authors review the different implants used for the intra-articular substitution of the anterior cruciate ligament (ACL), analyzing the autologous grafts, synthetic materials and tendinous allografts. We find ourselves facing a controversy, although the present tendency is the use of bone-patellar tendon-bone autografts. None of the substituted tissues, however, can completely resemble the anatomy of the original ACL