• Laser & Optoelectronics Progress
  • Vol. 61, Issue 5, 0527002 (2024)
Shuo Li and Rong Zhang*
Author Affiliations
  • College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, Jiangsu , China
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    DOI: 10.3788/LOP231007 Cite this Article Set citation alerts
    Shuo Li, Rong Zhang. Quantum Walk Wave-Particle Coherent Superposition[J]. Laser & Optoelectronics Progress, 2024, 61(5): 0527002 Copy Citation Text show less

    Abstract

    Evolution process and properties of wave-particle quantum walk (QW) are studied by theoretical calculation and quantum simulator's simulation. Quantum control can contribute to the realization of QWs in quantum wave-particle superposition state with a relative phase between walkers. The post-selection operation is used to realize the continuous transitions of QW from the state of waves with multi-path coherence to the state of particles without coherence in two different ways: coherence and mixing. Due to quantum interference, there are essential differences between coherence and mixing, and their specific features are characterized by position variance. We also demonstrate the coherent wave-particle QWs in the real quantum simulator. When the walker is in the wave-particle coherent state, two completely different properties can be observed simultaneously through one measurement. By adjusting the relative phase in the wave-particle coherent state, the diffusion rate of the walker can be controlled.
    U^tW=S^1H^1I^
    H^1=12111-1
    S^1=xLLx-1x+RRx+1x
    U^P=U^tPU^3PU^2PU^1P
    U^tP=S^tH^tI^
    S^t=xLtLx-1x+RtRx+1x
    U^t=00U^tW+11U^tP
    Ψ0=a0+b1αR+βL0
    Ψ(t)=a0ψW+b1ψP
    ψP=12t/2x(α+β)NR(α-β)NLn=1hψnx
    ψW=xgRx,tR+gLx,tLc1αR+βLc2αR+βLctx
    Φ=aψW+bψP
    ρ=a2ψWψ+b2ψPψ
    Pct,t=1NagRt,tαt-1+bα+β2t2+a2gRt,t2α2t-12t-1-1
    Pc-t,t=1NagL-t,tβt-1+bα-β2t2+a2gL-t,t2α2t-12t-1-1
    Pcx,t=1Nt-1NR+1agRx,tαNR-1βNL+12tbα+βNRα-βNL2+t-1NL-1agLx,tαNRβNL-1+12tbα+βNRα-βNL2+a2gRx,t21/2t-12t-1-t-1NR-1
    Pmixx,t=a2gLx,t2+gRx,t2+b2s2tα+βNRα-βNL2