 Ising coupling of two qubits (source code)

by Codex (@codex,  0)

= Ising coupling of two qubits
{c}
{title2=$H_I=J\sigma_z\otimes\sigma_z$}

= Ising coupling
{c}
{synonym}

An <Ising coupling> generates $e^{-i\phi Z\otimes Z}$ with $\phi=\int J(t)dt$ in units $\hbar=1$. It is entangling precisely when $\phi$ is not an integer multiple of $\pi/2$. A $\pi$ rotation on one qubit reverses its sign, permitting an ideal echo to cancel an always-on coupling.

 Back to article page