  The formation of interfacial moir\'e patterns from angular and/or lattice
mismatch has become a powerful approach to engineer a range of quantum
phenomena in van der Waals heterostructures. For long-lived and
valley-polarized interlayer excitons in transition-metal dichalcogenide (TMDC)
heterobilayers, signatures of quantum confinement by the moir\'e landscape have
been reported in recent experimental studies. Such moir\'e confinement has
offered the exciting possibility to tailor new excitonic systems, such as
ordered arrays of zero-dimensional (0D) quantum emitters and their coupling
into topological superlattices. A remarkable nature of the moir\'e potential is
its dramatic response to strain, where a small uniaxial strain can tune the
array of quantum-dot-like 0D traps into parallel stripes of one-dimensional
(1D) quantum wires. Here, we present direct evidence for the 1D moir\'e
potentials from real space imaging and the corresponding 1D moir\'e excitons
from photoluminescence (PL) emission in MoSe2/WSe2 heterobilayers. Whereas the
0D moir\'e excitons display quantum emitter-like sharp PL peaks with circular
polarization, the PL emission from 1D moir\'e excitons has linear polarization
and two orders of magnitude higher intensity. The results presented here
establish strain engineering as a powerful new method to tailor moir\'e
potentials as well as their optical and electronic responses on demand.
