Abstracts Book - IMRC 2018

• SD1-O029 Invited Talk
MAGNETISM AND SUPERCONDUCTIVITY IN DISORDERED
CARBON
James Chelikowsky 1 , Yuki Sakai 1
1 University of Texas at Austin, Institute for Computational Engineering and Sciences, United
States.
We investigate magnetism and superconductivity in amorphous carbon inspired
by a recently reported new form of amorphous carbon called Q-carbon. We use
“spin constrained” first-principles simulations to obtain intrinsic amorphous
carbon structures with magnetic properties similar to Q-carbon. We show that
the existence of sp 2 -like 3-fold coordinated carbon atoms play an important role
in the realization of magnetism in amorphous carbon. In addition, the detailed
geometries of these 3-fold carbon atoms affects the magnetic order in
amorphous carbon. We also examine the effect of boron doping in
superconducting forms of disordered carbon. By judiciously optimizing B
substitutional sites in simulated amorphous carbon we predict a
superconducting transition temperature near 37K at 14% boron concentration.
Our findings have direct implications for understanding the recently discovered
high T c superconductivity in Q-carbon.
Acknowledgment:
We acknowledge support the U.S. Department of Energy for work on
nanostructures grant DE-FG02-06ER46286, and on algorithms by a subaward
the Center for Computational Study of Excited-State Phenomena in Energy
Materials at the Lawrence Berkeley National Laboratory, which is funded by the
U.S.~Department of Energy, Office of Science, Basic Energy Sciences, Materials
Sciences and Engineering Division under Contract No.DE-AC02-05CH11231, as
part of the Computational Materials Sciences
Program. Computational resources are provided in part by the National Energy
Research Scientific Computing Center (NERSC) and the Texas Advanced
Computing Center (TACC).
Keywords: Simulation of disordered carbon, Superconductivity, Ferromagnetism
Presenting authors email: jrc@utexas.eduI