  Recent experiments have demonstrated sub decoherence time control of
individual single-electron orbital qubits. Here we propose a quantum dot based
scheme for generation and detection of pairs of orbitally entangled electrons
on a timescale much shorter than the decoherence time. The electrons are
entangled, via two-particle interference, and transferred to the detectors
during a single cotunneling event, making the scheme insensitive to charge
noise. For sufficiently long detector dot lifetimes, cross-correlation
detection of the dot charges can be performed with real-time counting
techniques, opening up for an unambiguous short-time Bell inequality test of
orbital entanglement.
