Jeudi 24 février 2022 à 14h00, Gerbold Ménard (ESPCI) donnera un séminaire sur "Detection of topological phase through three terminal measurement of hybrid systems"
Abstract :
The search for Majorana quasiparticles in hybrid semiconductor/superconductor systems has been a main preoccupation of the condensed matter community in the past decade, ever since the experimental work of Mourik et al. [1] in 2012. However, many theoretical works have criticized that work, as well as the following studies, and proposed various trivial explanations of the experimental data. In particular, one of the main points of criticism from these theoretical works is the absence of end-to-end correlation of the zero-bias signatures. In this talk I will describe a new platform that allows us to perform three-terminal measurements of hybrid nanowires Al/InAs [2,3,4]. These so-called SAG (selective area growth) nanowires have the advantage of presenting a native superconducting electrode in the middle of the wire which does not necessaite any destructive procedure for its electrical connection. Thanks to this third electrode, the two ends of the nanowire can share a common ground in the middle and as such be measured simulatenously. I will also discuss the possibility to access the full conductance matrix with both its local and non-local terms and relate it to the charge of the underlying electronic excitations.
[1] V. Mourik et al. Science, 336, (2012) 1003-1007.
[2] G. Anselmetti et al., Phys. Rev. B 100 (2019) 205412.
[3] G. Ménard et al., Phys. Rev. Lett., 124 (2020) 036802.
[4] D. Puglia et al., Phys. Rev. B 103 (2021) 235201.
