Robustness of spin-coupling distributions for perfect quantum state transfer | Phys. Rev. A 84, 022311 (2011)
Robustness of spin-coupling distributions for perfect quantum state transfer
Analia Zwick1,2,*, Gonzalo A. Álvarez1,†, Joachim Stolze1,‡, and Omar Osenda2,§
1Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany.
2Facultad de Matemática, Astronomía y Física and Instituto de Física Enrique Gaviola, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
Received 28 April 2011; published 8 August 2011
The transmission of quantum information between different parts of a quantum computer is of fundamental importance. Spin chains have been proposed as quantum channels for transferring information. Different configurations for the spin couplings were proposed in order to optimize the transfer. As imperfections in the creation of these specific spin-coupling distributions can never be completely avoided, it is important to find out which systems are optimally suited for information transfer by assessing their robustness against imperfections or disturbances. We analyze different spin coupling distributions of spin chain channels designed for perfect quantum state transfer. In particular, we study the transfer of an initial state from one end of the chain to the other end. We quantify the robustness of different coupling distributions against perturbations and we relate it to the properties of the energy eigenstates and eigenvalues. We find that the localization properties of the systems play an important role for robust quantum state transfer.
©2011 American Physical Society