Enhanced spreading in continuous-time quantum walks using aperiodic temporal modulation of defects

TL;DR

This paper demonstrates that aperiodic temporal modulation of defects in continuous-time quantum walks can enhance quantum spreading, extending Parrondo's paradox beyond periodic protocols and offering new control methods for wavepacket dynamics.

Contribution

It introduces aperiodic defect modulation in CTQWs, showing it reliably enhances spreading and maintains Parrondo's effect, unlike previous periodic approaches.

Findings

Aperiodic defect switching enhances quantum spreading.

The enhancement depends on autocorrelation and persistence of the sequence.

Aperiodic modulation maintains Parrondo's paradox in CTQWs.

Abstract

Parrondo's paradox, where the alternation of two losing strategies can produce a winning outcome, has recently been demonstrated in continuous-time quantum walks (CTQWs) through periodic defect modulation. We extend this phenomenon to aperiodic protocols. We show that deterministic, non-repetitive defect switching can enhance quantum spreading in CTQWs compared to the defect-free case. Furthermore, we establish that the degree of this enhancement is strongly influenced by the autocorrelation and persistence characteristics of the applied aperiodic sequence. Our findings indicate that aperiodic defect modulation reliably maintains Parrondo's effect and provides new ways to control wavepacket properties in CTQWs.