Title: Strain manipulation of Majorana fermions in graphene armchair nanoribbons,
Abstract: Graphene nanoribbons with armchair edges are studied for externally enhanced,
but realistic parameter values: enhanced Rashba spin-orbit coupling due to
proximity to a transition metal dichalcogenide like WS$_{2}$, and enhanced
Zeeman field due to exchange coupling with a magnetic insulator like EuS under
applied magnetic field. The presence of s--wave superconductivity, induced
either by proximity or by decoration with alkali metal atoms like Ca or Li,
leads to a topological superconducting phase with Majorana end modes. The
topological phase is highly sensitive to the application of uniaxial strain,
with a transition to the trivial state above a critical strain well below
$0.1\%$. This sensitivity allows for real space manipulation of Majorana
fermions by applying non-uniform strain profiles. Similar manipulation is also
possible by applying inhomogeneous Zeeman field or chemical potential.