Abstract
We develop a systematic approach to establish Bell inequalities for qubits based on the Cauchy-Schwarz inequality. We also use the concept of distinct “roots” of the Bell function to classify some well-known Bell inequalities for qubits. As applications of the approach, we present three unique and tight Bell inequalities for four and three qubits, respectively.
- Received 17 August 2008
DOI:https://doi.org/10.1103/PhysRevA.79.012115
©2009 American Physical Society