Hannover 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 15: Quantum Effects: Disorder
Q 15.5: Vortrag
Montag, 29. Februar 2016, 18:00–18:15, f442
Unitary 2-designs and Decoupling with Random Diagonal-Unitary Matrices — Yoshifumi Nakata1, •Christoph Hirche1, Ciara Morgan2, and Andreas Winter1 — 1Física Teòrica: Informació i Fenòmens Quàntics, Universitat Autònoma de Barcelona, ES-08193 Bellaterra (Barcelona), Spain — 2School of Mathematics and Statistics, University College Dublin, Belfield, Dublin 4. Ireland
We investigate unitary 2-designs and decoupling, two of the most important primitives in quantum Shannon theory, with random diagonal-unitaries. We first show that the alternate application of random diagonal-unitaries in the Pauli-Z and -X bases constitutes a unitary 2-design after a number of repetitions, implying that the process achieves decoupling. We then go on to show that even fewer repetitions are sufficient for achieving decoupling at the same rate as that with Haar random unitaries. We also provide a simple quantum circuit that implements a unitary 2-design and achieves decoupling, which is partitioned into a constant number of commuting parts.