Two-mode entanglement using a spin-1/2 approximation method in two-component condensates

We propose a spin-12 approximation method to study the quantum entanglement of two-component Bose–Einstein condensates trapped in double wells. This approximation is demonstrated to be valid under the stationary tunneling condition and for odd particle numbers of each component. The contours of entanglement with respect to tunneling rate and time are found to be hyperbolic-like. Strong and long time sustained entanglement can be achieved, with the maximal entanglement occurring at tunneling times t≈κΩ2(π2+kπ).