Quantum parallelism of the controlled-NOT operation: an experimental criterion for the evaluation of device performance

Abstract

It is shown that a quantum controlled-NOT gate simultaneously performs the logical functions of three distinct conditional local operations. Each of these local operations can be verified by measuring a corresponding truth table of four local inputs and four local outputs. The quantum parallelism of the gate can then be observed directly in a set of three simple experimental tests, each of which has a clear intuitive interpretation in terms of classical logical operations. Specifically, quantum parallelism is achieved if the average fidelity of the three classical operations exceeds 2/3. It is thus possible to evaluate the essential quantum parallelism of an experimental controlled-NOT gate by testing only three characteristic classical operations performed by the gate.

6 pages, no figures, added references and discussion

References in corpus (6)

• Quantum oscillations in two coupled charge qubits
• Quantum process tomography of a controlled-NOT gate
• Violation of local uncertainty relations as a signature of entanglement
• Experimental Teleportation of a Quantum Controlled-NOT Gate
• How robust is a quantum gate in the presence of noise?
• Experimental demonstration of a non-destructive controlled-NOT quantum gate for two independent photon-qubits

Cited by in corpus (7)

• Linear Optical Quantum Computing in a Single Spatial Mode
• Experimental Realization of a Controlled-NOT Gate with Four-Photon Six-Qubit Cluster States
• Optical Nondestructive Controlled-NOT Gate without Using Entangled Photons
• Teleportation-based realization of an optical quantum two-qubit entangling gate
• Heralded non-destructive quantum entangling gate with single-photon sources
• How to simulate a quantum computer using negative probabilities
• Analysis of an experimental quantum logic gate by complementary classical operations