Fig. 3: Illustrating the SBD-STM procedure.
From: Dictionary learning in Fourier-transform scanning tunneling spectroscopy
The simulated kernel (size 25 × 25 pixels) in a is convolved with the activation map in b and added to random noise with SNR ≈0.792 to produce the simulated noisy measurement shown in c. The simulated measurement is a 185 × 185 pixel image with a defect concentration of θ = 2.73%. d Recovered kernel and e recovered activation map obtained using SBD-STM with λ = 0.1, showing excellent agreement with simulation inputs in a, b. The Re-FTs of the truth kernel, noisy measurement, and the recovered kernel from SBD-STM, shown in f–h, respectively. The Re-FT spectra are all shown with − 3π/5a ≤ qx, qy ≤ 3π/5a, and all color bars are in arbitrary units. The SBD-STM-based FT shows both vastly improved SNR and a phase-sensitive recovery of the scattering interference.
