Signature of antiferromagnetic long-range order in the optical spectrum of strongly correlated electron systems

We show how the onset of a non-Slater antiferromagnetic ordering in a correlated material can be detected by optical spectroscopy. Using dynamical mean-field theory we identify two distinctive features: The antiferromagnetic ordering is associated with an enhanced spectral weight above the optical gap, and well separated spin-polaron peaks emerge in the optical spectrum. Both features are indeed observed in LaSrMnO_4 [G\"ossling et al., Phys. Rev. B 77, 035109 (2008)]Comment: 11 pages, 9 figure

From infinite to two dimensions through the functional renormalization group

We present a novel scheme for an unbiased and non-perturbative treatment of strongly correlated fermions. The proposed approach combines two of the most successful many-body methods, i.e., the dynamical mean field theory (DMFT) and the functional renormalization group (fRG). Physically, this allows for a systematic inclusion of non-local correlations via the flow equations of the fRG, after the local correlations are taken into account non-perturbatively by the DMFT. To demonstrate the feasibility of the approach, we present numerical results for the two-dimensional Hubbard model at half-filling.Comment: 5 pages, 4 figure

Paediatric endodontics. Part. 1: Portland Cements Apical Plug

Treatment of necrotic immature permanent anterior teeth with Portland cements apical plug. The long-term success of endodontic treatment depends on the quality of the apical and coronal seal. In necrotic immature teeth the treatment can be challenging for the clinician as the endodontic anatomy and the presence of bacterial infection need to be addressed with special techniques and materials in order to obtain an effective and biocompatible apical seal. Unfortunately, despite the best treatments, immature permanent teeth have a reduced resistance to fracture due to the arrest of root walls development

SEM Evaluation of the Hybrid Layer of Two Universal Adhesives on Sound and DI Type II Affected Dentin

Universal nanofilled adhesives were recently introduced in restorative dentistry to simplify clinical procedures and improve adhesion in different clinical situation. This study investigated the effectiveness of two universal adhesives on both sound and dentinogenesis imperfecta type II (DI-II)-affected teeth. To evaluate the effectiveness of adhesion on both sound and DI-II-affected teeth, four samples, two sound extracted molars and two extracted molars affected by DI-II were selected. Coronal enamel and dentin were exposed, and the samples were used for testing two different universal adhesives, Universal Bond (Tokuyama) and All-Bond Universal (Bisco). After the adhesive procedures, the samples were stored in saline at room temperature for one week prior to SEM investigation for the interfacial bonding layer. The samples were longitudinally sectioned into two parts, obtaining two sections for the evaluation of the adhesive interface to the SEM. The SEM-morphology of the hybrid layer on the enamel was similar for the two universal adhesives tested. The study of the hybrid layer on sound dentin confirmed the great versatility of All-Bond Universal and Universal Bond adhesives in managing adhesion even on pathological dental substrates. Both universal adhesives tested showed encouraging results on DI-II-affected dentin, creating an effective hybrid layer even on the atubular and less mineralized altered dentin