Information propagation through disordered quantum spin chains

摘要: One of the central aims quantum information theory is to exploit mechanical phenomena such as superposition and entanglement build a computer — device capable efficiently performing computational tasks which are not feasible on classical computer. In order achieve this goal it will be necessary connect together different components with channels quickly faithfully transmitting states. It has been suggested that good channel for purpose chain permanently coupled spins we begin by reviewing some protocols have previously developed transfer along spin chain. We then examine effects noise propagation chains, using toolkit methods include Lieb-Robinson bounds, Jordan-Wigner transform correlation functions. Several fundamentally models considered including static (time-independent) onsite disorder model two fluctuating (time-dependent) on-site disorder. Each distinctive effect leads exponential localisation whilst dynamic can lead diffusive or even ballistic information. finish how (whether noisy noisefree) viewed depolarising make detailed study geometrical structure all possible respect various bases, concentrating Pauli, Gell-Mann Heisenberg-Weyl bases. particular, show precisely when set forms simplex in compression space.