Excitation transfer in disordered spin chains with long-range exchange interactions

We examine spin excitation or polarization transfer via spin chains with long-range ex-change interactions in the presence of diagonal and off-diagonal disorder. To this end, we determine the mean localization length of the single-excitation eigenstates of the chain for various strengths of the disorder. We then identify the energy eigenstates of the system with large localization length and sufficient support at the chain boundaries that are suitable to transfer an excitation between the sender and receiver spins con-nected to the opposite ends of the chain. We quantify the performance of two transfer schemes involving weak static couplings of the sender and receiver spins to the chain, and time-dependent couplings realizing stimulated adiabatic passage of the excitation via the intermediate eigenstates of the chain which exhibits improved performance.

Automated summary

We investigate the transmission of spin excitation through spin chains with long-range exchange interactions in the presence of diagonal and off-diagonal disorder. By determining the mean localization length of single-excitation eigenstates, we identify energy eigenstates suitable for transferring excitation between the sender and receiver spins connected to opposite ends of the chain. We examine the performance of two transfer schemes involving weak static couplings and time-dependent couplings, and find that the latter, which utilizes stimulated adiabatic passage, shows improved performance.