Fig. 4: Spin dynamics under acoustic fields.
a Spin transport length, ℓs, and b angular precession frequency, ΩSO, as a function of the strain amplitude uxx,0 for transport along the QW (10 nm thick, black solid squares), QWR (red solid dots), and DQDs (30 nm thick QW, green solid triangles) investigated in this work. The error bars represent the standard deviation in determining the fitted parameters. The solid red line in (b) is a fit of the QWR data to Eq. (2); the green curve superimposed on the solid triangles is the prediction of Eq. (3) for the DQDs using the C3 parameter determined from the fit. Note that for the DQDs, the horizontal axis is the strain amplitude per acoustic beam and the ΩSO values were scaled by a factor of \(1/\sqrt{2}\) to account for the higher transport velocity as compared to the QW or QWR (cf. Eqs. (2) and (3)). The open and solid ⋆'s yield the ΩSO obtained from tight-binding (TB) calculations for the studied QWs (TB-QW) and QWRs (TB-QWR), respectively. The dashed lines in (a) are guides to the eye. The open symbols in (b) represent previously reported data for spin transport by a single SAW21 (series of open squares at uxx = 0.2 × 10−4), DQDs in a 20 nm thick QW21 (series of open triangles at uxx = 0.2 × 10−4), as well as for DQDs in a 20 nm-thick QW29 (orange triangle).
