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Related papers: Quantum walks in the density operator picture

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The "quantum walk" has emerged recently as a paradigmatic process for the dynamic simulation of complex quantum systems, entanglement production and quantum computation. Hitherto, photonic implementations of quantum walks have mainly been…

We study the entanglement dynamics of discrete time quantum walks acting on bounded finite sized graphs. We demonstrate that, depending on system parameters, the dynamics may be monotonic, oscillatory but highly regular, or quasi-periodic.…

Quantum Physics · Physics 2012-03-07 Peter P. Rohde , Alessandro Fedrizzi , Timothy C. Ralph

Coherent evolution governs the behaviour of all quantum systems, but in nature it is often subjected to influence of a classical environment. For analysing quantum transport phenomena quantum walks emerge as suitable model systems. In…

We consider quantum walks defined on arbitrary infinite graphs, parameterized by a family of scattering matrices attached to the vertices. Multiplying each scattering matrix by an i.i.d. random phase, we obtain a random scattering quantum…

Mathematical Physics · Physics 2026-02-16 Alain Joye , Andreas Schaefer , Simone Warzel

Among the discrete evolution equations describing a quantum system $\rH_S$ undergoing repeated quantum interactions with a chain of exterior systems, we study and characterize those which are directed by classical random variables in…

Mathematical Physics · Physics 2007-12-21 Stéphane Attal , Ameur Dhahri

Multilayer network is a potent platform which paves a way to study the interactions among entities in various networks with multiple types of relationships. In this study, the dynamics of discrete-time quantum walk on a multilayer network…

Quantum Physics · Physics 2023-10-05 M. N. Jayakody , Priodyuti Pradhan , Dana Ben Porath , E. Cohen

We show that the discrete-time evolution of an open quantum system generated by a single quantum channel $T$ can be embedded in the discrete-time evolution of an enlarged closed quantum system, i.e. we construct a unitary dilation of the…

Mathematical Physics · Physics 2020-08-17 Frederik vom Ende , Gunther Dirr

We extend the idea of a discrete-time quantum walk on a graph by placing a qubit on each vertex, and allowing the walker to interact with the qubit at its current position. We show that allowing for a controlled-Z interaction at each time…

Quantum Physics · Physics 2016-08-26 Joshua Lockhart , Mauro Paternostro

For a quantum walk on a graph, there exist many kinds of operators for the discrete-time evolution. We give a general relation between the characteristic polynomial of the evolution matrix of a quantum walk on edges and that of a kind of…

Mathematical Physics · Physics 2013-11-28 Yusuke Higuchi , Norio Konno , Iwao Sato , Etsuo Segawa

The quantum walks in the lattice spaces are represented as unitary evolutions. We find a generator for the evolution and apply it to further understand the walks. We first extend the discrete time quantum walks to continuous time walks.…

Mathematical Physics · Physics 2013-05-09 Chul Ki Ko , Hyun Jae Yoo

Universal quantum computation can be realised using both continuous-time and discrete-time quantum walks. We present a version based on single particle discrete-time quantum walk to realize multi-qubit computation tasks. The scalability of…

Quantum Physics · Physics 2023-08-21 Prateek Chawla , Shivani Singh , Aman Agarwal , Sarvesh Srinivasan , C. M. Chandrashekar

Quantum walks have been shown to have a wide range of applications, from artificial intelligence, to photosynthesis, and quantum transport. Quantum stochastic walks (QSWs) generalize this concept to additional non-unitary evolution. In this…

Quantum Physics · Physics 2021-05-26 Peter K. Schuhmacher , Luke C. G. Govia , Bruno G. Taketani , Frank K. Wilhelm

A quantum walk places a traverser into a superposition of both graph location and traversal "spin." The walk is defined by an initial condition, an evolution determined by a unitary coin/shift-operator, and a measurement based on the…

Quantum Physics · Physics 2015-11-25 Marko A. Rodriguez , Jennifer H. Watkins

Discrete quantum walks are dynamical protocols for controlling a single quantum particle. Despite of its simplicity, quantum walks display rich topological phenomena and provide one of the simplest systems to study and understand…

Quantum Physics · Physics 2011-12-09 Takuya Kitagawa

Quantum walks have been shown to be fruitful tools in analysing the dynamic properties of quantum systems. This article proposes to use quantum walks as an approach to Quantum Neural Networks (QNNs). QNNs replace binary McCulloch-Pitts…

Quantum Physics · Physics 2014-04-02 Maria Schuld , Ilya Sinayskiy , Francesco Petruccione

A discrete-time quantum walk on a graph is the repeated application of a unitary evolution operator to a Hilbert space corresponding to the graph. Hitting times for discrete quantum walks on graphs give an average time before the walk…

Quantum Physics · Physics 2007-11-13 Hari Krovi

This dissertation presents investigations on dynamics of discrete-time quantum walk and some of its applications. Quantum walks has been exploited as an useful tool for quantum algorithms in quantum computing. Beyond quantum computational…

Quantum Physics · Physics 2010-06-25 C. M. Chandrashekar

Quantum walks function as essential means to implement quantum simulators, allowing one to study complex and often directly inaccessible quantum processes in controllable systems. In this contribution, the notion of a driven Gaussian…

Discrete-time quantum walk in one-dimension is studied from a path-integral perspective. This enables derivation of a closed-form expression for amplitudes corresponding to any coin-position basis of the state vector of the quantum walker…

Quantum Physics · Physics 2018-03-02 Karthik S. Joshi , S. K. Srivatsa , R. Srikanth

Quantum walks have been employed widely to develop new tools for quantum information processing recently. A natural quantum walk dynamics of interacting particles can be used to implement efficiently the universal quantum computation. In…

Quantum Physics · Physics 2016-10-04 Alexey A. Melnikov , Leonid E. Fedichkin