Experimental Generation And Application Of Ultrabright Multi-Photon Entangled State

This thesis describes an ultra-bright multi-photon entanglement setup. We discuss in detail about the generation method of eight-photon Schrodinger-cat state and multi-qubit hyper-entangled state. Multi-photon entangled states are a unique experimental system to study linear optical quantum information processing such as programmable quantum processor, Bell inequeality test, quantum computation in correlation space and topological quantum error-correction. The main research results are list as follows:1. We report on experimental demonstration of an advanced linear-optical programmable quantum gate array that involves two single-qubit programmable quantum gates interleaved with a fixed quantum operation. Based on this processor, we directly probe the (anti)-commutation relations for Pauli operators and we completely characterize the (anti)-commutators by quantum process tomography.2. We experimentally demonstrate a Y-shaped graph state. Based on this state and a linear-type graph state, we report on the experimental realization of two different Bell inequality tests, which represent higher violation than previous Bell tests.3. We report an experimental demonstration of quantum computation in correlation space. With four-qubit and six-qubit states, we have realized a universal set of single-qubit rotations, two-qubit entangling gates and also Deutsch’s algorithm.4. We demonstrate for the first time the creation of an eight-photon Schrodinger-cat state with genuine multipartite entanglement by using new ultra-bright sources of entangled photon pairs, an eight-photon interferometer and post-selection detection.5. We report the experimental demonstration of topological error correction with an eight-photon cluster state. We show that a correlation can be protected against a single error on any quantum bit. Also, when all quantum bits are simultaneously subjected to errors with equal probability, the effective error rate can be significantly reduced. Our work demonstrates the viability of topological error correction for fault-tolerant quantum information processing.