A magnetic memory device according to embodiments includes a first reference magnetic layer on a substrate, a second reference magnetic layer on the first reference magnetic layer, a free layer between the first reference magnetic layer and the second reference magnetic layer, a first tunnel barrier layer between the first reference magnetic layer and the free layer, and a second tunnel barrier layer between the second reference magnetic layer and the free layer. The first reference magnetic, second reference magnetic and free layers each have a magnetization direction substantially perpendicular to a top surface of the substrate. A resistance-area product (RA) value of the first tunnel barrier layer is greater than that of the second tunnel barrier layer.