Bell measurement

The Bell measurement is an important concept in quantum information science: It is a joint quantum-mechanical measurement of two qubits that determines in which of the four Bell states the two qubits are in.

If the qubits were not in a Bell state before, they get projected into a Bell state (according to the projection rule of quantum measurements), and as Bell states are entangled, a Bell measurement is an entangling operation.

It is the crucial part of quantum teleportation (see there).

In current experiments which use photons as qubits, Bell measurements can only be partly realized as two of the Bell states cannot be distinguished with optical techniques. In Bell measurements of ion qubits in ion trap experiments, the distinction of all four states is possible.

Category:Evolutions and Operations

Last modified: 
Monday, October 26, 2015 - 17:56