Analysis and minimization of bending losses in discrete quantum networks

  title={Analysis and minimization of bending losses in discrete quantum networks},
  author={Georgios M. Nikolopoulos and Anton{\'i}n Hoskovec and Igor Jex},
  journal={Physical Review A},
We study theoretically the transfer of quantum information along bends in two-dimensional discrete lattices. Our analysis shows that the fidelity of the transfer decreases considerably, as a result of interactions in the neighbourhood of the bend. It is also demonstrated that such losses can be controlled efficiently by the inclusion of a defect. The present results are of relevance to various physical implementations of quantum networks, where geometric imperfections with finite spatial extent… 

Figures from this paper

Decoupling bent quantum networks

The analytically found correction procedure is tested using numerical simulations on a number of realistic cases and confirms that the occurring errors can be efficiently compensated for a wide range of system parameters.

State Transfer Hamiltonians in Photonic Lattices

Faithful communication is a necessary precondition for large scale all-optical networking and quantum information processing. Related theoretical investigations in different areas of physics have led

Selective dynamical decoupling for quantum state transfer

This work presents selective dynamical decoupling schemes which are capable of stabilizing imperfect quantum state transfer protocols on the model of a bent linear qubit chain and demonstrates their efficiency in numerical simulations.

Transfer of optical signals around bends in two-dimensional linear photonic networks

The ability to navigate light signals in two-dimensional networks of waveguide arrays is a prerequisite for the development of all-optical integrated circuits for information processing and

Faithful communication Hamiltonian in photonic lattices.

This work presents the first experimental realization of a finite discrete lattices channel with judiciously engineered couplings in the framework of femtosecond-laser-written waveguide arrays.

Advanced dynamical decoupling strategies for simulating Hamiltonian interactions

In the field of quantum information, a major challenge is to protect and shield quantum systems from environmental influences, which cause dissipation and decoherence. One approach to address this

Analytic next-to-nearest-neighbor X X models with perfect state transfer and fractional revival

Certain nonuniformly coupled spin chains can exhibit perfect transfer of quantum states from end to end. Motivated by recent experimental implementations in evanescently coupled waveguide arrays, we

Spin chain systems for quantum computing and quantum information applications

Spin chains are presented as reliable devices for quantum communication with high transfer fidelities, entanglement generation and distribution over distant parties and protected storage of quantum information.

Czech Technical University in Prague Faculty of Nuclear Sciences and Physical Engineering DOCTORAL THESIS State Transfer in Imperfect Networks Prague 2020

This work explores the adverse effects of several perturbations of the ideal models inspired by the physical character of these systems, and proposes Dynamical Decoupling, a quantum error correction method, restricted to using single-particle operations only.

Automatic spin-chain learning to explore the quantum speed limit

This work considers a specific task from quantum physics, i.e. quantum state transfer in a one-dimensional spin chain, and converts the state transfer process into a Markov decision process that can be understood by the machine.



Quantum Phase Transitions

Part I. Introduction: 1. Basic concepts 2. The mapping to classical statistical mechanics: single site models 3. Overview Part II. Quantum Ising and Rotor Models: 4. The Ising chain in a transverse

Photonics : optical electronics in modern communications

1. Electromagnetic Fields and Waves 2. Rays and Optical Beams 3. Dielectric Waveguides and Optical Fibers 4. Optical Resonators 5. Interaction of Radiation and Atomic Systems 6. Theory of Laser


  • Rev. A 73, 032306 (2006); V. Kostak, G. M. Nikolopoulos and I. Jex, Phys. Rev. A 75, 042319 (2007); T. Brougham, G. M. Nikolopoulos and I. Jex, Phys. Rev. A 80, 052325
  • 2009


  • Rev. A 74, 012321 (2006); G. Gualdi et al., Phys. Rev. A 78, 022325
  • 2008

Ωmax represents the upper limit on the achievable couplings within a physical realization of the chains, and is determined by physical or technological constraints

    This is a universal ratio for a given chain i.e., it does not depend on the actual position of the bend. If necessary


      • Phys. 48, 13 (2007); D. Burgarth, Eur. Phys. J. Special Topics 151, 147 (2007); A. Kay, Int. J. Quant. Inform. 8, 641
      • 2010

      The effect ofV (θ) can be treated perturbatively only for κ ≪ 1. Moreover, for the protocols under consideration and the entire regime of parameters

        Detunings for κ 0.7 have to be taken with a pinch of salt, since they far exceed Ωmax and thus may not be realizable within certain physical platforms

          Stresses that remain after their original source (e.g., external forces, heat gradient) has been removed