Majorana corner pairs in a two-dimensional $s$-wave cold atomic superfluid

We propose a method to prepare Majorana pairs at the corners of imprinted defects on a two-dimensional cold atom optical lattice with $s$-wave superfluid pairing. Different from previous proposals that manipulate the effective Dirac masses, our scheme relies on the sign flip of the spin-orbit coupling at the corners, which can be tuned in experiments by adjusting the angle of incident Raman lasers. The Majorana corner pairs are found to be located at the interface between two regimes with opposite spin orbit coupling strengths in an anticlockwise direction and are robust against certain symmetry-persevered perturbations. Our work provides a new way for implementing and manipulating Majorana pairs with existing cold-atom techniques.