Quantum critical behavior and Majorana fermions in a resonant level coupled to a dissipative environment

by Gleb Finkelstein

at Condensed Matter Seminar

Mon, 08 May 2017, 11:30
Physics building (#54) room 207

Abstract

We investigate tunneling through a resonant level embedded in a dissipative environment which suppresses tunneling rates at low temperatures Specifically the resonant level is formed in a carbon nanotube quantum dot and the dissipative environment is realized by fabricating resistive leads For the symmetric coupling of the resonant level to the two leads we find that the resonant peak reaches the unitary conductance e 2 h despite the presence of dissipative modes Simultaneously the width of the resonance tends to zero as a non trivial power of temperature We draw a connection between our system and a resonant tunneling in a Luttinger liquid and interpret the observed unitary resonance of vanishing width in terms of a quantum critical point QCP We further investigate an exotic state of electronic matter obtained by fine tuning the system exactly to the QCP We report on several transport scaling laws both near and far from equilibrium including a non Fermi liquid quasi linear scattering rate at the QCP interpreted in terms of a Majorana mode localized at the resonant level

Created on 03-05-2017 by Bar Lev, Yevgeny (ybarlev)
Updaded on 03-05-2017 by Bar Lev, Yevgeny (ybarlev)