English
Related papers

Related papers: Repeated measurements and random scattering in qua…

200 papers

We explore the use of machine-learning techniques to detect quantum speedup in random walks on graphs. Specifically, we investigate the performance of three different neural-network architectures (variations on fully connected and…

Quantum Physics · Physics 2023-09-06 Hanna Linn , Yu Zheng , Anton Frisk Kockum

We explore static noise in a discrete quantum random walk over a homogeneous cyclic graph, focusing on spectral and dynamical properties. Using a three-parameter unitary coin, we control the spectral structure of the noiseless step operator…

Quantum Physics · Physics 2025-08-22 G. Juarez Rangel , B. M. Rodríguez-Lara

Monitored quantum systems evolve along stochastic trajectories correlated with the observer's knowledge of the system's state. Under such dynamics, certain quantum resources like entanglement may depend on the observer's state of knowledge.…

Quantum Physics · Physics 2024-09-04 Christian Carisch , Oded Zilberberg , Alessandro Romito

Classical random walks on finite graphs have an underrated property: a walk from any vertex can reach every other vertex in finite time, provided they are connected. Discrete-time quantum walks on finite connected graphs however, can have…

Quantum Physics · Physics 2023-01-18 Prithviraj Prabhu , Todd A. Brun

Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. However, the main impetus behind this interest is their use in quantum algorithms, which have always…

Quantum Physics · Physics 2011-07-20 Viv Kendon

Hitting times for discrete quantum walks on graphs give an average time before the walk reaches an ending condition. To be analogous to the hitting time for a classical walk, the quantum hitting time must involve repeated measurements as…

Quantum Physics · Physics 2009-11-11 Hari Krovi , Todd A. Brun

There are presently two models for quantum walks on graphs. The "coined" walk uses discrete time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the…

Quantum Physics · Physics 2009-11-10 Mark Hillery , Janos Bergou , Edgar Feldman

Quantum walks are promising for information processing tasks because on regular graphs they spread quadratically faster than random walks. Static disorder, however, can turn the tables: unlike random walks, quantum walks can suffer Anderson…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 Tibor Rakovszky , Janos K. Asboth

We investigate reflected random walks in the quarter plane, with particular emphasis on the time spent along the reflection boundary axes. Assuming the drift of the random walk lies within the cone, the local time converges -- without the…

Probability · Mathematics 2025-07-08 Viet Hung Hoang , Kilian Raschel

We investigate if the degradation of a quantum directional reference frame through repeated use can be modeled as a classical direction undergoing a random walk on a sphere. We demonstrate that the behaviour of the fidelity for a degrading…

Quantum Physics · Physics 2007-10-10 Stephen D. Bartlett , Terry Rudolph , Barry C. Sanders , Peter S. Turner

Quantum walks are powerful kernels in quantum computing protocols that possess strong capabilities in speeding up various simulation and optimisation tasks. One striking example is given by quantum walkers evolving on glued trees for their…

Quantum walk research has mainly focused on evolutions due to repeated applications of time-independent unitary coin operators. However, the idea of controlling the single particle evolution using time-dependent unitary coins has still been…

Quantum Physics · Physics 2019-09-19 Shrabanti Dhar , Abdul Khaleque , Tushar Kanti Bose

Structure in quantum entanglement entropy is often leveraged to focus on a small corner of the exponentially large Hilbert space and efficiently parameterize the problem of finding ground states. A typical example is the use of matrix…

Statistical Mechanics · Physics 2023-04-17 Bart Olsthoorn

Despite of the extreme success of the spectral graph theory, there are relatively few papers applying spectral analysis to hypergraphs. Chung first introduced Laplacians for regular hypergraphs and showed some useful applications. Other…

Combinatorics · Mathematics 2011-02-23 Linyuan Lu , Xing Peng

We consider discrete-time nearest-neighbor quantum walks on random environments in one dimension. Using the method based on a path counting, we present both quenched and annealed weak limit theorems for the quantum walk.

Quantum Physics · Physics 2010-05-12 Norio Konno

In this work, we study the effect of a moving detector on a discrete time one dimensional Quantum Random Walk where the movement is realized in the form of hopping/shifts. The occupation probability $f(x,t;n,s)$ is estimated as the number…

Quantum Physics · Physics 2023-07-10 Md Aquib Molla , Sanchari Goswami

A quantum walk is the quantum analogue of a random walk. While it is relatively well understood how quantum walks can speed up random walk hitting times, it is a long-standing open question to what extent quantum walks can speed up the…

Quantum Physics · Physics 2024-02-13 Simon Apers , Laurent Miclo

Measurements with randomly chosen settings determine many important properties of quantum states without the need for a shared reference frame or calibration. They naturally emerge in the context of quantum communication and quantum…

We study a class of Unitary Quantum Walks on arbitrary graphs, parameterized by a family of scattering matrices. These Scattering Quantum Walks model the discrete dynamics of a system on the edges of the graph, with a scattering process at…

Mathematical Physics · Physics 2026-04-10 Alain Joye

In this paper, we introduce a quantum walk whose local scattering at each vertex is denoted by a unitary circulant matrix; namely the circulant quantum walk. We also introduce another quantum walk induced by the circulant quantum walk;…

Quantum Physics · Physics 2022-08-17 Yusuke Mizutani , Etsuo Segawa , Yusuke Higuchi , Leo Matsuoka , Tomoyuki Horikiri