Article
Quantum Science & Technology
Farrukh Mukhamedov, Abdessatar Souissi, Tarek Hamdi, Amenallah Andolsi
Summary: The paper is a continuation of previous work on Quantum Markov Chains (QMC) associated with Open Quantum Random Walks and investigates the recurrence property of QMC. In this study, the recurrence and accessibility of QMC over trees are defined and the recurrence property of QMC associated with Open Quantum Random Walks is discussed.
QUANTUM INFORMATION PROCESSING
(2023)
Article
Quantum Science & Technology
Tomoki Yamagami, Etsuo Segawa, Norio Konno
Summary: The study extends the scheme of quantum teleportation by quantum walks and introduces the mathematical definition and necessary conditions for achieving quantum teleportation rigorously. The results classify the parameters necessary for the successful accomplishment of quantum teleportation.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Multidisciplinary Sciences
Leo Regnier, Maxim Dolgushev, S. Redner, Olivier Benichou
Summary: The territory explored by a random walk can be quantified by the number of distinct sites visited. We introduce a fundamental quantity, tau(n), which is the time required by a random walk to find a previously unvisited site after visiting n distinct sites, encompassing the dynamics of visitation statistics. We develop a theoretical approach using a mapping with a trapping problem to study it, and find that the distribution of tau(n) can be accounted for by simple analytical expressions, applicable to various diffusion processes.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Chusei Kiumi
Summary: This article introduces a method for finding the existence of eigenvalues in three-state quantum walks and uncovers the necessary and sufficient condition for the eigenvalue problem of a two-phase three-state quantum walk with one defect.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Optics
Christopher R. Schwarze, David S. Simon, Alexander Sergienko
Summary: This article introduces interferometric devices that combine optical feedback (cavities) with unbiased multiports, which allows light to reflect back from the port it originated. By replacing the traditional, directionally biased beam-splitter in a Michelson interferometer with an unbiased multiport, the functional dependence of scattering amplitudes changes. This greatly enhances the resolution of phase measurement and allows real-time alteration of phase response curves by tuning an externally controllable phase shift.
Article
Quantum Science & Technology
Ugo Nzongani, Julien Zylberman, Carlo-Elia Doncecchi, Armando Perez, Fabrice Debbasch, Pablo Arnault
Summary: The aim of this paper is to build quantum circuits for implementing discrete-time quantum walks with arbitrary position-dependent coin operators. The circuits proposed in the paper can achieve this goal but at the cost of exponential depth or exponential number of ancillae. The paper also extends previous results to position-dependent 2 x 2-block-diagonal unitaries and discusses applications in quantum simulation and quantum spatial-search schemes.
QUANTUM INFORMATION PROCESSING
(2023)
Article
Physics, Multidisciplinary
Prateek Chawla, C. M. Chandrashekar
Summary: Aromaticity is a well-known phenomenon that influences the unique chemical and physical properties of molecules, with the stability of polycyclic aromatic hydrocarbons being attributed to delocalized pi-electron clouds in the 2p(z) orbitals of carbon atoms. This study suggests quantum walk as a mechanism for electron delocalization and successfully predicts reactive sites and stability order in benzoid polycyclic aromatic hydrocarbons through computations.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Yali Jia, Zhi-Jian Li
Summary: The research shows that in one-dimensional multi-period quantum walks, for odd-period quantum walks, the 0-energy and pi-energy edge states coexist equally on the boundary, while for even-period quantum walks, these two types of edge states may exist alone or together. By considering the coin parameter as a step function of position, the relationship between the number of edge states and high winding number has been discussed. Additionally, the validity of the bulk-edge correspondence is confirmed.
Article
Quantum Science & Technology
Rebekah Herrman, Thomas G. Wong
Summary: This paper investigates the simplification methods of quantum walks on dynamic graphs, proposes six scenarios for graph simplification, and provides examples of how to simplify dynamic graphs to achieve parallel single-qubit gates.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Quantum Science & Technology
Alessandro Candeloro, Claudia Benedetti, Marco G. Genoni, Matteo G. A. Paris
Summary: This paper addresses the quantum search of a target node on a cycle graph using a quantum walk assisted by continuous measurement and feedback. A dynamical oracle implemented through a feedback Hamiltonian is used. The performance of the protocol is quantified and different constraints on the control strategy are discussed. The results show that the protocol can quickly localize the walker on the target node.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Physics, Multidisciplinary
Jacob W. Turner, Jacob Biamonte
Summary: This article investigates the symmetry of physical processes under time inversion and explores a range of models and experimental implementations related to time symmetry breaking in quantum physics, providing a topological classification of Hamiltonian operators and characterizing gauge potentials on combinatorial graphs. These studies fill an important gap in our understanding of the role this effect plays in quantum information and computation.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Optics
S. Panahiyan, S. Fritzsche
Summary: The study focuses on simulating topological phases in three dimensions using quantum walks, with an emphasis on protocols that can simulate different families of topological phases in various dimensions. The introduction of step-dependent coins in the evolution operators of quantum walks adds dynamism to the simulated topological phenomena, allowing for control over the numbers, types, and occurrences of topological phases and boundary states based on the step number of the quantum walk.
Article
Quantum Science & Technology
Gabriele Bressanini, Claudia Benedetti, Matteo G. A. Paris
Summary: This paper addresses the decoherence and classicalization of continuous-time quantum walks on graphs. Three different models of decoherence are investigated, and the quantum-classical (QC) dynamical distance is employed to assess the classicalization of the CTQW due to decoherence. The results show that intrinsic decoherence only partially preserves quantum features, while decoherence in the position basis completely destroys the quantumness of the walker. Additionally, the speed of the classicalization process is also examined.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Computer Science, Theory & Methods
T. S. Jacq, C. F. Lardizabal
Summary: This work focuses on studying open quantum random walks on the integer line and obtaining criteria for site recurrence, particularly in the case where the internal degree of freedom of each site is of dimension 2. The results also extend to irreducible walks with an internal degree of arbitrary finite dimension, as well as the absorption problem for walks on the semi-infinite line.
QUANTUM INFORMATION & COMPUTATION
(2021)
Article
Physics, Multidisciplinary
Thibault Fredon, Julien Zylberman, Pablo Arnault, Fabrice Debbasch
Summary: This article presents results on a quantum spatial-search algorithm, implemented on a 2D square grid using a 2D Dirac discrete-time quantum walk coupled to a Coulomb electric field. The research findings show that with the addition of the electric term, the algorithm is able to reach a second localization peak around the marked node in a time of O(root N). The study also explores the effects of noise on the Coulomb potential and finds that the walk is highly robust to spatial noise, moderately robust to spatiotemporal noise, and the first localization peak is even highly robust to spatiotemporal noise.
Article
Physics, Multidisciplinary
M. Stefanak, J. Novotny, I. Jex
NEW JOURNAL OF PHYSICS
(2016)
Article
Quantum Science & Technology
M. Stefanak, S. Skoupy
QUANTUM INFORMATION PROCESSING
(2017)
Article
Multidisciplinary Sciences
Thomas Nitsche, Sonja Barkhofen, Regina Kruse, Linda Sansoni, Martin Stefanak, Aurel Gabris, Vaclav Potocek, Tamas Kiss, Igor Jex, Christine Silberhorn
Article
Multidisciplinary Sciences
Norio Konno, Etsuo Segawa, Martin Stefanak
Summary: The paper explores the survival probability of Grover walks with sinks and their connection to Grover walks with tails, showing that the relationship between them can be described using eigenspaces.
Article
Physics, Multidisciplinary
E. Segawa, S. Koyama, N. Konno, M. Stefanak
Summary: We provide a detailed analysis of the survival probability of the Grover walk on the ladder graph with an absorbing sink. By constructing an orthonormal basis in the dark subspace, a closed formula for the survival probability is derived. It is shown that the survival probability can change from increasing to decreasing by attaching a loop to one of the corners of the ladder.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Physics, Multidisciplinary
Martin Stefanak
Summary: This paper investigates the monitored recurrence of a one-parameter set of three-state quantum walks on a line. The calculations are simplified by choosing a suitable basis of the coin space. The study shows that the Polya number depends on the coin parameter and the probability of the walker being initially in a specific coin state where the walk returns to the origin with certainty. Finally, a brief investigation of the exact quantum state recurrence is presented.
Article
Physics, Multidisciplinary
Martin Stefanak, Stanislav Skoupy
Summary: In this study, state transfer on a hypercube through quantum walk is investigated. The search for a single marked vertex is analyzed first, demonstrating the possibility of state transfer between arbitrary vertices. The transfer of state between antipodal vertices is then considered, showing that high-fidelity transfer can be achieved in a shorter time by adjusting the weight of the loop. Finally, state transfer between vertices of arbitrary distance is investigated, with results for antipodal vertices being applicable when the distance is at least 2.
Article
Optics
J. Mares, J. Novotny, M. Stefanak, I Jex
Summary: Quantum walks exhibit properties without classical analogues. We provide a recipe for the construction of a complete basis of trapped states allowing to determine the asymptotic probability of trapping for arbitrary finite connected simple graphs, thus significantly generalizing the previously known result restricted to planar 3-regular graphs.
Article
Optics
S. Skoupy, M. Stefanak
Summary: The study focuses on the coined quantum-walk search and state-transfer algorithms, showing that marked vertices can be found with high probability in large graphs and successful state transfer between different partitions. However, when the sender and receiver are in the same partition, the fidelity does not reach exactly 1, leading to the proposal of a state-transfer algorithm with an active switch to address this issue.
Article
Optics
B. Kollar, A. Gilyen, I Tkacova, T. Kiss, I Jex, M. Stefanak
Article
Optics
Mohamed Sabri, Etsuo Segawa, Martin Stefanak
Proceedings Paper
Engineering, Electrical & Electronic
Thomas Nitsche, Regina Kruse, Linda Sansoni, Martin Stefanak, Tamas Kiss, Igor Jex, Sonia Barkhofen, Christine Silberhorn
2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2017)
Article
Optics
M. Stefanak, S. Skoupy
Article
Optics
M. Stefanak, I. Jex
Article
Optics
J. Mares, J. Novotny, M. Stefanak, I Jex
