ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarMárkus Bence GáborWigner RCP SZFIUltralong spin lifetime and 
superconductivity in doped grapheneTuesday, 2 March 2021, 10:00, video 
conference, https://letsmeet.wigner.hu/szeminariumToday’s great challenges of 
energy storage and informational technologies require new materials. I report 
on the preparation and physical properties of Li, Na, Ca, and Yb doped 
few-layer graphene. We found ultralong (3−27 ns) spin relaxation time in the 
lithium and sodium doped species [1], and superconductivity in the Ca and Yb 
doped materials. The emergence of Fano lineshapes in the G-line Raman 
spectral region as an indication of strong electron-phonon coupling, attest 
the high level of doping for all the metals probed. We find that Na dopes 
solely the monolayer graphene as it is known to be inert against graphitic 
carbon. In the Ca and Yb doped materials a superconductive phase transition 
is observed at ∼ 11 K and at ∼ 6 K, respectively, utilizing conventional 
SQUID magnetometry. Superconductivity is confirmed by the presence of 
non-linear microwave absorption observed in the ESR spectra. Furthermore, we 
observed differences in the critical fields of the prepared materials 
compared to their graphite relatives. The obtained materials might find 
applications in the field of spintronics, energy storage, and printable 
superconductive circuits.References [1] B. G. Márkus, P. Szirmai, K. 
Edelthalhammer, P. Eckerlein, A. Hirsch, F. Hauke, N. M. Nemes, Julio C. 
Chacón-Torres, B. Náfrádi, L. Forró, T. Pichler, and F. Simon: Ultralong spin 
lifetime in light alkali atom doped graphene, ACS Nano 14(6), 7492-7501, 
2020. Minden érdeklődőt szívesen látunk! - Everyone is welcome to 
attend.Róbert Juhászsem-admin AT szfki.hu