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Enhancing delocalization and entanglement in asymmetric discrete-time quantum walks
Optics Express
|July 2, 2026
Summary
Asymmetric discrete-time quantum walks (DTQWs) enhance both delocalization and entanglement. Experiments show specific asymmetric initial states and coin parameters boost these properties, even with polarization-dependent loss.
Area of Science:
- Quantum Information Science
- Quantum Optics
- Condensed Matter Physics
Background:
- Discrete-time quantum walks (DTQWs) are a powerful quantum computing primitive.
- Entanglement and delocalization are key quantum phenomena with applications in quantum information processing.
- Asymmetry in quantum systems can lead to novel behaviors and enhanced properties.
Purpose of the Study:
- To investigate the enhancement of delocalization and coin-position entanglement in asymmetric DTQWs.
- To explore the effects of asymmetric coin operations, initial states, and polarization-dependent losses.
- To experimentally realize and analyze an asymmetric DTQW.
Main Methods:
- Numerical calculation of inverse participation ratio and entanglement entropy for varying asymmetry factors.
- Experimental implementation of a 16-step asymmetric DTQW using a time-multiplexing fiber loop.
- Analysis of photon probability distribution and its dependence on coin and loss parameters.
Main Results:
- Simultaneous enhancement of coin-position entanglement and delocalization was achieved with asymmetric initial states and specific coin parameters.
- Asymmetric polarization-dependent loss led to decreased photon probability on the left and increased localization on the right.
- Entanglement and delocalization demonstrated improved robustness against polarization-dependent loss under specific coin parameters.
Conclusions:
- Asymmetric DTQWs provide an effective platform for enhancing photonic delocalization and hybrid entanglement.
- The interplay between asymmetry, coin parameters, and loss is crucial for controlling quantum walk properties.
- DTQWs offer a versatile system for fundamental quantum physics research and potential quantum technologies.
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