Figure 2. Anisotropic strain engineering of a QD under orthogonal uniaxial stresses.

(a,b) FSS and phase θ are plotted as a function of the voltage V_AC at a fixed voltage V_BD of 0 and −25 V, respectively. With the increasing voltages on legs A&C, FSS decreases monotonically to around zero and then increases again. And the phase shows an abrupt change from 0 to −90°, when FSS reaches the minimum value. The inset in a gives the definition of θ. The ellipse indicates an elongated QD with its major axis aligned along a crystallographic direction. The red solid line indicates the exciton polarization. The error bars originate from the fitting process. (c) Exciton wavelength is plotted as a function of V_AC for the two different V_BD. The solid lines are linear fits. The arrows indicate exciton wavelengths at which the FSS are erased. (d) The changes in FSS when both V_BD and V_AC are scanned. The dashed line on the bottom plane indicates a linear shift of the voltage combination (V_AC, V_BD) at which FSS reaches the minimum values.