  Cooper pair splitting (CPS) can induce non-local correlation between two
normal conductors coupling to a superconductor. CPS into a double
one-dimensional electron gas is an appropriate platform for extracting large
amount of entangled electron pairs and one of the key ingredients for
engineering Majorana Fermions with no magnetic field. Here we study CPS using a
Josephson junction of a gate-tunable ballistic InAs double nanowire. The
measured switching current into the two nanowires significantly larger than sum
of that into the respective nanowires, indicating the inter-wire
superconductivity dominant compared to the intra-wire superconductivity. From
dependence on the number of propagating channels in the nanowires, the observed
CPS is assigned to one-dimensional electron-electron interaction. Our results
will pave the way for utilizing one-dimensional electron-electron interaction
to reveal physics of high-efficient CPS and engineer Majorana Fermions in
double nanowire systems via CPS.
