SCES Webinar Series

Dra. Priscila F. S. Rosa (Los Alamos National Laboratory, Los Alamos, NM 87545 USA)

Título: Unraveling the mysteries of UTe2

Resumo: Spin-triplet superconductors are a promising route in the search for topological superconductivity, and UTe2 is a recently discovered contender. In this talk, I will first give a brief overview of UTe2 before presenting new insights from ac calorimetry, electrical resistivity, and x-ray absorption measurements of UTe2 under applied pressure. I will end with a discussion of some of the most pressing outstanding open questions.

Dr. Stephen E. Rowley (Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, United Kingdom)

Título: Superconductivity mediated by polar modes in doped ferroelectrics

Resumo: The occurrence of superconductivity in doped SrTiO3 and related materials at low carrier densities points to the presence of an unusually strong pairing interaction that has eluded understanding for several decades.  We present experimental results showing the pressure dependence of the superconducting transition temperature, Tc, that sheds light on the nature of this interaction.  We find that Tc increases dramatically when the energy gap of ferroelectric critical modes is suppressed, i.e., as the ferroelectric quantum critical point is approached, in a way reminiscent of behaviour observed in magnetic counterparts.  However, in contrast to the latter, the coupling of itinerant electrons to the critical modes in ferroelectrics is predicted to be small.  We present a superconductivity model to make quantitative comparisons with experiments and show that an enhancement of Tc near to a ferroelectric quantum critical point arises due to the virtual exchange of longitudinal hybrid-polar-modes, even in the absence of a direct coupling to the transverse critical modes.

O evento será transmitido pelo Zoom:https://us02web.zoom.us/j/4396875843?pwd=T0pwTFNyTk5majkxNW1mZWhneTBBdz09 / Meeting ID: 439 687 5843 - Password: 660629   e pela página do Instituto de Física no Facebook: https://www.facebook.com/FisicaUnicamp

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