English
Related papers

Related papers: Engineering stable quantum currents at bulk bounda…

200 papers

We look at two possible routes to classical behavior for the discrete quantum random walk on the line: decoherence in the quantum ``coin'' which drives the walk, or the use of higher-dimensional coins to dilute the effects of interference.…

Quantum Physics · Physics 2009-11-07 Todd A. Brun , Hilary A. Carteret , Andris Ambainis

A proof that continuous time quantum walks are universal for quantum computation, using unweighted graphs of low degree, has recently been presented by Childs [PRL 102 180501 (2009)]. We present a version based instead on the discrete time…

Quantum Physics · Physics 2010-05-06 Neil B. Lovett , Sally Cooper , Matthew Everitt , Matthew Trevers , Viv Kendon

We investigate the non-equilibrium charge dynamics of a triple quantum dot and demonstrate how electron transport through these systems can give rise to non-trivial tunnelling paths. Using a real-time charge sensing method we establish…

Mesoscale and Nanoscale Physics · Physics 2016-09-13 M. A. Broome , S. K. Gorman , J. G. Keizer , T. F. Watson , S. J. Hile , W. J. Baker , M. Y. Simmons

A new family of discrete-time quantum walks (DTQWs) on the line with an exact discrete $U(N)$ gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac…

Quantum Physics · Physics 2025-02-28 Pablo Arnault , Giuseppe Di Molfetta , Marc Brachet , Fabrice Debbasch

The quantum walk was originally proposed as a quantum mechanical analogue of the classical random walk, and has since become a powerful tool in quantum information science. In this paper, we show that discrete time quantum walks provide a…

Mesoscale and Nanoscale Physics · Physics 2010-09-30 Takuya Kitagawa , Mark S. Rudner , Erez Berg , Eugene Demler

We present a theory of coherent quantum transport in ferromagnetic/ non-magnetic/ ferromagnetic heterojunctions. We predict quantum coherence to give rise to a quantum spin valve effect that, unlike its familiar classical analog, occurs…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Francisco Mireles , George Kirczenow

A non-perturbative nonlinear statistical approach is presented to describe turbulent magnetic systems embedded in a uniform mean magnetic field. A general formula in the form of an ordinary differential equation for magnetic field-line…

Astrophysics · Physics 2009-11-13 A. Shalchi , I. Kourakis

We explore the prospects to control by use of time-dependent fields quantum transport phenomena in nanoscale systems. In particular, we study for driven conductors the electron current and its noise properties. We review recent…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sigmund Kohler , Jörg Lehmann , Peter Hänggi

We implement the discrete-time quantum walk model using the continuous-time evolution of the Hamiltonian that includes both the shift and the coin generators. Based on the Trotter-Suzuki first-order approximation, we consider an…

Quantum Physics · Physics 2022-03-03 Jalil Khatibi Moqadam , Marcos Cesar de Oliveira

We present a comprehensive classification of one-dimensional coined quantum walks on the infinite line, focusing on the spatial probability distributions they induce. Building on prior results, we identify all initial coin states that lead…

Quantum Physics · Physics 2025-08-01 Lukas Hantzko , Lennart Binkowski

We extend a simple model of a charge trap coupled to a single-electron box to energy ranges and parameters such that it gives new insights and predictions readily observable in many experimental systems. We show that a single background…

Mesoscale and Nanoscale Physics · Physics 2009-08-25 M. Pierre , M. Hofheinz , X. Jehl , M. Sanquer , G. Molas , M. Vinet , S. Deleonibus

In this article, we propose a quantum communication protocol via 2-step discrete time quantum walks with two coins on a graph of 10 vertices containing both cycles and paths. Quantum walks are known for their ability to integrate quantum…

Quantum Physics · Physics 2025-01-22 Rachana Soni , Neelam Choudhary , Navneet Pratap Singh

We study a 2-D disordered time-discrete quantum walk based on 1-D `generalized elephant quantum walk' where an entangling coin operator is assumed and which paves the way to a new set of properties. We show that considering a given disorder…

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

In this paper, we will critically discuss recent theoretical and experimental developments on the transport of one dimensional quantum systems. In particular, we will focus on open issues and controversial results related to the finite…

Strongly Correlated Electrons · Physics 2007-05-23 X. Zotos

Using the Calogero model as an example, we show that the transport in interacting non-dissipative electronic systems is essentially non-linear. Non-linear effects are due to the curvature of the electronic spectrum near the Fermi energy. As…

Strongly Correlated Electrons · Physics 2007-05-23 Eldad Bettelheim , Alexander G. Abanov , Paul Wiegmann

We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase…

Mathematical Physics · Physics 2018-06-13 S. Richard , A. Suzuki , R. Tiedra de Aldecoa

Randomly breaking connections in a graph alters its transport properties, a model used to describe percolation. In the case of quantum walks, dynamic percolation graphs represent a special type of imperfections, where the connections appear…

Quantum Physics · Physics 2014-06-03 Bálint Kollár , Jaroslav Novotný , Tamás Kiss , Igor Jex

In this paper, we study discrete-time quantum walks on one-dimensional lattices. We find that the coherent dynamics depends on the initial states and coin parameters. For infinite size of lattice, we derive an explicit expression for the…

Cellular Automata and Lattice Gases · Physics 2015-05-18 Xin-Ping Xu

In transport experiments the quantum nature of matter becomes directly evident when changes in conductance occur only in discrete steps, with a size determined solely by Planck's constant h. The observations of quantized steps in the…