Hydrogen Bonds and High Tc A new take on an old problem

by Daniel Kaplan

at Condensed Matter Theory Seminar

Wed, 28 Nov 2018, 13:30
Physics building (#54) room 207


High temperature superconductivity eludes a coherent theoretical explanation Since its discovery in 1986 by Bendroz and Mueller competing ideas have been put forward to explain the apparent violation in these materials of the BCS Bardeen Cooper Schrieffer limit of T c 30K All these ideas concluded that superconductivity in these materials is non conventional i e exhibits properties not covered by BCS theory Recently Drozdov Drozdov et al Nature 2016 showed that H 2 S under high pressures 170 GPa becomes a conventional superconductor showing the Meissner effect isotope effect clearly defined gap and ultrasonic attenuation with T c 200K an unprecedented record and unsurpassed to date Our work DK and Y Imry PNAS 2018 suggests that BCS theory i e weak electron phonon coupling can explain some of the features shown in these and other experiments We offer a qualitative model of electron proton scattering H atoms found in materials like H 2 S which shows enhancement of superconductivity We discuss two models: a simple one involving a hydrogen atom trapped in a harmonic well and hydrogen bonds in H 2 S modeled via Lennard Jones interaction We show that there exist conditions under which superconductivity is enhanced yielding High T c We compare our qualitative results with experiments and discuss possible applications of our model in the search for room temperature T c We present future plans involving more accurate and quantitative analysis of the model

Created on 22-11-2018 by Bar Lev, Yevgeny (ybarlev)
Updaded on 22-11-2018 by Bar Lev, Yevgeny (ybarlev)