No abstract

We propose a non-deterministic CNOT gate based on a quantum cloner, a quantum switch based on all optical routing of single photon by single photon, a quantum-dot spin in a double-sided optical microcavity with two photonic qubits, delay lines and other linear optical photonic devices. Our CNOT provides a fidelity of 78% with directly useful outputs for a quantum computing circuit and requires no ancillary qubits or electron spin measurements.

In this paper, we show how a quantum CNOT-based relational database is built, then we show how to query its quantum tables using the most used SQL-like queries, e.g. INSERT, UPDATE, DELETE and SELECT. We specify each time the evolution of the probability amplitude corresponding to the records before and after the query has been executed and we propose corresponding circuits implementation.

Generalized behavior of a nondeterministic CNOT gate based on physical implementation is subject of this work. We define an abstract probabilistic model of the CNOT gate and describe a general proposition of realizability assessment based on experimental features. Theoretical results are directly confronted to experimental realization. Two CNOT models are brought out for this purpose.