Direct Observation of Full-Gap Superconductivity and Pseudogap in Two-Dimensional Fullerides.

Alkali-fulleride superconductors with a maximum critical temperature T_{c}∼40 K exhibit a similar electronic phase diagram to that of unconventional high-T_{c} superconductors. Here we employ cryogenic scanning tunneling microscopy to show that trilayer K_{3}C_{60} displays fully gapped strong coupling s-wave superconductivity, accompanied by a pseudogap above T_{c}∼22 K and within vortices. A precise control of the electronic correlations and potassium doping enables us to reveal that superconductivity occurs near a superconductor-Mott-insulator transition and reaches maximum at half-filling. The s-wave symmetry retains over the entire phase diagram, which, in conjunction with an abrupt decline of the superconductivity below half-filling, indicates that alkali fullerides are predominantly phonon-mediated superconductors, although the electronic correlations also come into play.

Interferential effect of the over-erupted third molar on chewing movement.

OBJECTIVE: To clarify whether over-eruption of the mandibular third molar can disturb chewing movement. METHODS: Eighteen patients with a unilateral mandibular over-erupted third molar confirmed by both study cast observation and T-scan occlusal detection were selected from a sample of patients with complaints of temporomandibular disorder (TMD) symptoms. A unilateral gum-chewing trace was recorded separately for left and right side chewing by an electrognathography system. The average chewing pattern (ACP) was created based on segments from the recorded chewing trace to represent the chewing movement characteristics of each individual. Two factors, the TMD symptomatic side and the over-eruption side, were analysed for their effects on values of difference in the parameters (Δvalue) regarding the ACP between chewing with right and left side. Three-dimensional amplitudes of ACP and the cross point value of ACP with the vertical axis (termed the cross zero point value) which described the turning point of the chewing cycle from the balancing side to the working side, were compared between sides. RESULTS: The over-eruption side had an effect on the Δvalue of the medial amplitude, the lateral amplitude, and the cross zero point (P<0.05), but the symptomatic side didn't (P>0.05). When chewing on the over-eruption side, the medial amplitude was shorter, the lateral amplitude was larger, and the cross zero point value was smaller than those when chewing on the other side (P<0.05). CONCLUSION: The present data indicate an effect of the over-erupted mandibular third molar on the chewing pattern while that from the symptom(s) is limited.

Molecular beam epitaxial growth of topological insulators.

With the molecular beam epitaxy technique, layer-by-layer growth of atomically flat topological insulator Bi(2) Te(3) and Bi(2) Se(3) thin films has been realized on Si(111) and graphene substrates, respectively. The growth criteria by which intrinsic topological insulators can readily be obtained is established. By using in situ angle-resolved photoemission spectroscopy and scanning tunneling microscopy measurements, the band structure and surface morphology of Bi(2) Te(3) and Bi(2) Se(3) thin films of different thickness can be studied. Molecular beam epitaxy technique was shown to not only provide an excellent method to prepare high quality topological insulators but show possibilities of engineering their electronic and spin structures as well, which is of significant importance for potential applications of topological insulators based on well-developed Si technology.