Weak localization∕antilocalization in a nearly symmetric In[sub 0.53]Ga[sub 0.47]As∕In[sub 0.52]Al[sub 0.48]As quantum well

We report weak antilocalization (WAL) measurements in a nearly symmetric In0.53Ga0.47As/In0.52Al0.48As quantum well. In this system, an enhancement of the spin‐orbit scattering time, equivalently the weakening of the WAL effect, is expected at carrier densities Ns where equal magnitudes between the Rashba and Dresselhaus parameters (α = ±β) are realized. Our magnetotransport measurements indeed exhibited a weakening of the WAL effect as a function of Ns, though the weakening took place at only one carrier density. Our interpretation is that the value of β is so small that the two carrier densities corresponding to α = β and α = −β are very close to each other. It turned out that the deduced values for the bulk Dresselhaus parameter γ in In0.53Ga0.47As/In0.52Al0.48As quantum wells is considerably smaller than the k⋅p value of 27 eVA3.