Quantum Contextuality with Stabilizer States

Quantum Contextuality with Stabilizer States

The Pauli groups are ubiquitous in quantum information theory because of their usefulness in describing quantum states and operations and their readily understood symmetry properties. In addition, the most well-understood quantum error correcting codes—stabilizer codes—are built using Pauli operators. The eigenstates of these operators—stabilizer states—display a structure (e.g., mutual orthogo...

“Haunted” quantum contextuality

Two entangled particles in threedimensional Hilbert space (per particle) are considered in an EPR-type arrangement. On each side the Kochen-Specker observables {J 1 , J 2 2 , J 2 3 } and {J̄ 2 1 , J̄ 2 2 , J 2 3 } with [J 2 1 , J̄ 2 1 ] 6= 0 are measured. The outcomes of measurements of J 3 (via J 2 1 , J 2 2 ) and J 2 3 (via J̄ 1 , J̄ 2 2 ) are compared. We investigate the possibility that, althoug...

Bounding the quantum dimension with contextuality

Decoherence and quantum contextuality

Decoherence is the most widely accepted mechanism to explain the loss of coherence in quantum systems. Here we show how simple (quantum) trajectory–based models can help to understand the physics behind decoherence processes. In particular, we will analyze with these models the relationship between decoherence and quantum contextuality in the double–slit experiment, where two (quantum) contexts...

Measuring Observable Quantum Contextuality

Contextuality is a central property in comparative analysis of classical, quantum, and supercorrelated systems. We examine and compare two well-motivated approaches to contextuality. One approach (“contextuality-by-default”) is based on the idea that one and the same physical property measured under different conditions (contexts) is represented by different random variables. The other approach...