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We consider quantum random walks in an infinite-dimensional phase space constructed using Weyl representation of the coordinate and momentum operators in the space of functions on a Hilbert space which are square integrable with respect to…

Quantum Physics · Physics 2024-06-18 Vladimir Busovikov , Alexander Pechen , Vsevolod Sakbaev

We give the first example of faster transport with a quantum walk on an inherently directed graph, on the directed line with a variable number of self-loops at each vertex. These self-loops can be thought of as adding a number of small…

Quantum Physics · Physics 2009-02-24 Stephan Hoyer , David A. Meyer

A two-dimensional discrete-time quantum walk (DTQW) can be realized by alternating a two-state DTQW in one spatial dimension followed by an evolution in the other dimension. This was shown to reproduce a probability distribution for a…

Quantum Physics · Physics 2015-12-09 Takuya Machida , C. M. Chandrashekar

This article studies the breaking of the Lorentz symmetry at the Planck length in quantum mechanics. We use three-dimensional p-adic vectors as position variables, while the time remains a real number. In this setting, the Planck length is…

Quantum Physics · Physics 2024-07-08 W. A. Zúñiga-Galindo

We propose a general framework for quantum walks on d-dimensional spaces. We investigate asymptotic behavior of these walks. Among them, existence of limit distribution of homogeneous walks is proved. In this theorem, the support of the…

Mathematical Physics · Physics 2021-05-19 Hiroki Sako

The ADM approach to canonical general relativity combined with Dirac's method of quantizing constrained systems leads to the Wheeler-DeWitt equation. A number of mathematical as well as physical difficulties that arise in connection with…

General Relativity and Quantum Cosmology · Physics 2009-10-28 N. P. Landsman

For a discrete two-state quantum walk (QW) on the half-line with a general condition at the boundary, we formulate and prove a weak limit theorem describing the terminal behavior of its transition probabilities. In this context,…

Quantum Physics · Physics 2015-10-05 Chaobin Liu , Nelson Petulante

There has recently been considerable interest in quantum walks in connection with quantum computing. The walk can be considered as a quantum version of the so-called correlated random walk. We clarify a strong structural similarity between…

Quantum Physics · Physics 2010-06-08 Norio Konno

The theory of random walks on finite graphs is well developed with numerous applications. In quantum walks, the propagation is governed by quantum mechanical rules; generalizing random walks to the quantum setting. They have been…

Quantum Physics · Physics 2022-05-10 Avah Banerjee

We analyze several families of two-dimensional quantum random walks. The feasible region (the region where probabilities do not decay exponentially with time) grows linearly with time, as is the case with one-dimensional QRW. The limiting…

Combinatorics · Mathematics 2010-09-15 Yuliy Baryshnikov , Wil Brady , Andrew Bressler , Robin Pemantle

We derive the continuous spacetime limit of the one dimensional lazy discrete time quantum walk, obtaining explicit macroscopic evolution equations for a three state model in the presence of decoherence. While continuum limits of two state…

Quantum Physics · Physics 2026-01-19 Lara Janiurek , Viv Kendon

Research has shown that quantum walks can accelerate certain quantum algorithms and act as a universal paradigm for quantum processing. The discrete-time quantum walk (DTQW) model, owing to its discrete nature, stands out as one of the most…

Quantum Physics · Physics 2024-08-06 Biswayan Nandi , Sandipan Singha , Ankan Datta , Amit Saha , Amlan Chakrabarti

In this paper, we consider the continuous limit of a nonlinear quantum walk (NLQW) that incorporates a linear quantum walk as a special case. In particular, we rigorously prove that the walker (solution) of the NLQW on a lattice $\delta…

Mathematical Physics · Physics 2020-05-20 Masaya Maeda , Akito Suzuki

Quantum walks are known to propagate quadratically faster than their classical counterparts and are used to model dynamics in various quantum systems. The spread of the quantum walk in position space shows anomalous diffusion behavior. By…

Quantum Physics · Physics 2022-05-24 Abhaya S. Hegde , C. M. Chandrashekar

Up to now, relatively few exponential quantum speed-ups have been achieved. Out of them, the welded tree problem (Childs, Cleve, Deotto, Farhi, Gutmann, and Spielman'2003) is one of the unusual examples, as the exponential speed-up is…

Quantum Physics · Physics 2024-05-01 Aleksandrs Belovs

We present a theory describing the superconducting (SC) interaction of Dirac electrons in a quasi-two-dimensional system consisting of a stack of N planes. The occurrence of a SC phase is investigated both at T=0 and T\neq 0, in the case of…

Superconductivity · Physics 2020-10-05 E. C. Marino , Lizardo H. C. M. Nunes

We perform a minisuperspace analysis of an information-theoretic nonlinear Wheeler-deWitt (WDW) equation for de Sitter universes. The nonlinear WDW equation, which is in the form of a difference-differential equation, is transformed into a…

General Relativity and Quantum Cosmology · Physics 2012-04-02 Rajesh R. Parwani , Siti Nursaba Tarih

We investigate the one-dimensional Coulomb potential with application to a class of quasirelativistic systems, so-called Dirac-Weyl materials, described by matrix Hamiltonians. We obtain the exact solution of the shifted and truncated…

Mesoscale and Nanoscale Physics · Physics 2014-11-24 C. A. Downing , M. E. Portnoi

This letter treats the quantum random walk on the line determined by a 2 times 2 unitary matrix U. A combinatorial expression for the mth moment of the quantum random walk is presented by using 4 matrices, P, Q, R and S given by U. The…

Quantum Physics · Physics 2007-05-23 Norio Konno

The question of when the Kirkwood-Dirac quasiprobability serves as the most appropriate description for quantum measurements has remained unresolved, particularly across different measurement strengths. While known to generate anomalous…

Quantum Physics · Physics 2026-01-27 Bo Zhang , Yusuf Turek