Figure 4

(a) The molecule structure (left) and its parameter table (right). There are multiple ¹H nuclear spins. Only the ¹H spin that is directly corrected to the ³¹P spin is used as a qubit. The J coupling between the ¹H and ³¹P nuclear spins is 697.4 Hz. The control pulses are on resonance with ¹H and ³¹P spins and thus their frequency offsets are both 0 Hz. The spin Hamiltonian is \(H_{0}=\pi J \sigma _{z}^{H}\sigma _{z}^{P}/2\), where \(J=697.4\text{ Hz}\). (b) The Fourier transform spectrum of the ¹H spin which is directly connected to ³¹P, obtained using Gemini. The small spikes between the two major peaks are due to non-idea removal of the signals of the ¹H spins in the methyl groups. The inset shows the thermal spectrum of all the ¹H spins. The peaks (labeled as ‘P’) of methyl ¹H spins are fitted using Lorentzian line shapes and removed on purpose in signal processing to get a clear signal of the ¹H of interest. (c) The Fourier transform spectrum of the ³¹P spin obtained using Gemini