0000000000083698
AUTHOR
M. C. Bañuls
Simulation of many-qubit quantum computation with matrix product states
Matrix product states provide a natural entanglement basis to represent a quantum register and operate quantum gates on it. This scheme can be materialized to simulate a quantum adiabatic algorithm solving hard instances of a NP-Complete problem. Errors inherent to truncations of the exact action of interacting gates are controlled by the size of the matrices in the representation. The property of finding the right solution for an instance and the expected value of the energy are found to be remarkably robust against these errors. As a symbolic example, we simulate the algorithm solving a 100-qubit hard instance, that is, finding the correct product state out of ~ 10^30 possibilities. Accum…
CP and T violation in neutrino oscillations
The conditions to induce appreciable CP-and T-odd effects in neutrino oscillations are discussed. The propagation in matter leads to fake CP-and CPT-odd asymmetries, besides a Bohm-Aharonov type modification of the interference pattern. We study the separation of fake and genuine CP violation by means of energy and distance dependence.
Electromagnetic decays of heavy baryons
9 páginas, 3 figuras, 7 tablas.-- PACS number(s): 12.39.Fe, 12.39.Hg, 13.40.Hq, 14.20.Lq
Magnetic moments of heavy baryons
6 páginas, 2 figuras, 4 tablas.-- PACS number(s): 12.39.Fe, 12.39.Hg, 14.20.Lq, 14.20.Mr
Quantum walk with a time-dependent coin
We introduce quantum walks with a time-dependent coin, and show how they include, as a particular case, the generalized quantum walk recently studied by Wojcik et al. {[}Phys. Rev. Lett. \textbf{93}, 180601(2004){]} which exhibits interesting dynamical localization and quasiperiodic dynamics. Our proposal allows for a much easier implementation of this particular rich dynamics than the original one. Moreover, it allows for an additional control on the walk, which can be used to compensate for phases appearing due to external interactions. To illustrate its feasibility, we discuss an example using an optical cavity. We also derive an approximated solution in the continuous limit (long--wavel…