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Area of Science:

  • Quantum physics
  • Quantum information science
  • Condensed matter physics

Background:

  • Quantum random walks (QRW) are fundamental models in quantum computation.
  • Entanglement is a key resource for quantum information processing.
  • Disorder in quantum systems can lead to novel phenomena.

Purpose of the Study:

  • To investigate entanglement dynamics in disordered one-dimensional discrete-time quantum random walks.
  • To compare entanglement in disordered QRW with ordered QRW.
  • To explore the influence of initial states and determine conditions for achieving maximal entanglement.

Main Methods:

  • Modeling disorder in QRW using a classical coin to randomly select quantum coin operations.
  • Analyzing the entanglement between spin and position degrees of freedom.
  • Asymptotic analysis of entanglement with increasing number of steps.

Main Results:

  • Maximal entanglement is achieved asymptotically in disordered QRW, outperforming ordered QRW.
  • Maximal entanglement is independent of the initial state of the quantum walker.
  • The number of steps required to approach the asymptotic entanglement limit is studied.

Conclusions:

  • Dynamically disordered QRW provides a robust platform for generating high levels of entanglement.
  • The findings offer insights into controlling and utilizing entanglement in quantum systems.
  • Experimental proposals are presented for validating these theoretical predictions.