Localized persistent spin currents in defect-free quasiperiodic rings with Aharonov–Casher effect

• Strongly localized persistent spin current in quasiperiodic AC rings is proposed.
• Localized persistent spin currents are much larger than those produced by traditional mesoscopic rings.
• Characteristics of the localized persistent currents depend on the radius filling factor and SOI strength.
• The maximum persistent current increases exponentially with the system order.
• The magnitude of the persistent currents is related to the sharpness of the resonance.

We propose strongly localized persistent spin current in one-dimensional defect-free quasiperiodic Thue–Morse rings with Aharonov–Casher effect. The results show that the characteristics of these localized persistent currents depend not only on the radius filling factor, but also on the strength of the spin–orbit interaction. The maximum persistent spin currents in systems always appear in the ring near the middle position of the system array whether or not the Thue–Morse rings array is symmetrical. The magnitude of the persistent currents is proportional to the sharpness of the resonance peak, which is dependent on the bandwidth of the allowed band in the band structure. The maximum persistent spin currents also increase exponentially as the generation order of the system increases.