Width dependence of the 0.5 × (2e/h) conductance plateau in InAs quantum point contacts in presence of lateral spin-orbit coupling.

The evolution of the 0.5G (G = 2e/h) conductance plateau and the accompanying hysteresis loop in a series of asymmetrically biased InAs based quantum point contacts (QPCs) in the presence of lateral spin-orbit coupling (LSOC) is studied using a number of QPCs with varying lithographic channel width but fixed channel length. It is found that the size of the hysteresis loops is larger for QPCs of smaller aspect ratio (QPC channel width/length) and gradually disappears as their aspect ratio increases.