Fig. 1: RF pulse shapes designed using the GENETICS-AI software.
From: AI-designed NMR spectroscopy RF pulses for fast acquisition at high and ultra-high magnetic fields
RF pulse amplitudes and shapes (left), offset responses (center), and J coupling evolution profiles (right) for A. the band-selective 90o pulse UA90ev1, B. the broadband 180o pulse URev1, C. the broadband 180o pulse URev2, and D. the band-selective 180o UARev1. The effects of the pulses on the magnetization components are color-coded in the graph with the offset response. The oscillations of the Mx and My components of the magnetization indicate the chemical shift evolution during the pulse. The J coupling evolution was calculated using the two spin operators, 2IxSz and 2IySz, during the pulse duration, with the UA90ev1 pulse starting from an initial magnetization ρinitial: Iz, the URev1 from ρinitial: Ix, the URev2 from ρinitial: Ix, and the UARev1 pulse from ρinitial: Ix. Note that pulsing on a single channel refocuses the J coupling evolution, whereas pulsing on both channels restores the J coupling evolution. The green traces indicate the offset response for ideal instantaneous pulses. The blue traces are the offset response for pulsing on a single channel (I or S), and the red traces are the offset response for pulsing on both channels (I and S). The duration and operational bandwidth of the pulses are reported in Supplementary Table 1, and the 2D response profiles are shown in Supplementary Fig. 1.
