Liu, Chaobin; Petulante, Nelson On the von Neumann entropy of certain quantum walks subject to decoherence. (English) Zbl 1204.81107 Math. Struct. Comput. Sci. 20, No. 6, 1099-1115 (2010). Summary: We consider a discrete-time quantum walk on the \(N\)-cycle governed by the condition that at every time step of the walk, the option persists, with probability \(p\), of exercising a projective measurement on the coin degree of freedom. For a bipartite quantum system of this kind, we prove that the von Neumann entropy of the total density operator converges to its maximum value. Thus, when influenced by decoherence, the mutual information between the two subsystems corresponding to the space of the coin and the space of the walker must eventually diminish to zero. Put plainly, any level of decoherence greater than zero forces the system to become completely ‘disentangled’ eventually. Cited in 3 Documents MSC: 81S22 Open systems, reduced dynamics, master equations, decoherence 82B41 Random walks, random surfaces, lattice animals, etc. in equilibrium statistical mechanics 94A17 Measures of information, entropy 81P45 Quantum information, communication, networks (quantum-theoretic aspects) 81P15 Quantum measurement theory, state operations, state preparations PDF BibTeX XML Cite \textit{C. Liu} and \textit{N. Petulante}, Math. Struct. Comput. Sci. 20, No. 6, 1099--1115 (2010; Zbl 1204.81107) Full Text: DOI arXiv OpenURL References: [1] DOI: 10.1103/PhysRevB.80.125309 [2] DOI: 10.1103/PhysRevA.78.052316 [3] DOI: 10.1103/PhysRevA.65.032310 [4] DOI: 10.1142/S0219749903000383 · Zbl 1069.81505 [5] DOI: 10.1103/PhysRevA.74.030301 [6] DOI: 10.1088/1751-8113/43/7/075301 · Zbl 1187.82046 [7] Aharanov, Proceedings of the 33rd Annual ACM Symposium on Theory of Computing pp 50– (2001) [8] DOI: 10.1103/PhysRevA.81.062129 [9] DOI: 10.1103/PhysRevA.73.042302 [10] DOI: 10.1103/PhysRevA.67.042305 [11] DOI: 10.1103/PhysRevA.72.062317 [12] DOI: 10.1016/j.physa.2004.08.070 [13] DOI: 10.1103/PhysRevA.76.042306 [14] DOI: 10.1103/PhysRevE.81.031113 [15] DOI: 10.1103/PhysRevA.74.022310 [16] Konno, Springer-Verlag Lecture Notes in Mathematics 1954 pp 309– (2008) · Zbl 1329.82011 [17] DOI: 10.1103/PhysRevA.67.042315 [18] Kendon, Quantum Communication, Measurement & Computing (QCMC–02) (2002) [19] Kendon, Mathematical Structures in Computer Science 17 pp 1169– (2006) [20] DOI: 10.1080/00107151031000110776 [21] DOI: 10.1103/PhysRevA.58.915 [22] DOI: 10.1103/PhysRevA.72.012327 [23] DOI: 10.1103/PhysRevA.66.052319 [24] DOI: 10.1103/PhysRevA.67.042316 [25] DOI: 10.1023/A:1019609420309 · Zbl 1329.82006 [26] DOI: 10.1007/s00220-009-0930-1 · Zbl 1207.81029 [27] DOI: 10.1088/1367-2630/7/1/156 [28] Zurek, Decoherence Poincaré Seminar 2005, Progress in Mathematical Physics pp 1– (2003) [29] DOI: 10.1088/1367-2630/9/4/087 [30] DOI: 10.1103/PhysRevA.81.032321 [31] Venegas-Andraca, Quantum Walks for Computer Scientists (2008) [32] DOI: 10.1088/1367-2630/8/5/081 [33] DOI: 10.1103/PhysRevA.77.062302 [34] DOI: 10.1103/PhysRevA.67.032304 [35] DOI: 10.1103/PhysRevLett.91.130602 [36] Ambainis, Proceedings of the 33rd Annual ACM Symposium on Theory of Computing pp 37– (2001) This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.